A team of six salvage experts boarded, on Wednesday, an oil drilling rig  that went aground off an uninhabited island in the Gulf of Alaska.

The team was lowered to the Kulluk by a Coast Guard helicopter to conduct a structural assessment of the rig. The experts were on board the rig for about three hours.

Earlier efforts to board the rig were put on hold due to severe weather conditions over the past several days. Conditions were calmer on Wednesday.

The Kulluk broke loose of its tether to a tug boat in stormy seas last week and grounded onto a sand and gravel beach.

A slight break in the weather – 30 mph winds and 6-foot waves with 12-foot swells -- gave a team of Coast Guard, local and company officials optimism that salvage teams could be put in place, Jason Moore, a unified command spokesman told NBC News on Wednesday.

“It’s not great, but it’s better than what it has been over the last several days,” Moore said. “It is a bit of a break and were hoping we can take advantage of the improving weather”  

The Kulluk remained stranded but stable off Sitkalidak Island, which is along the southeastern coast of Kodiak Island in the Gulf of Alaska, Moore said. A Coast Guard cutter stationed to observe overnight Tuesday reported no leaks, he said.

A Coast Guard plane and helicopter flew over the Kulluk on Tuesday but poor weather didn’t permit marine experts to board the vessel.

Officials were hoping to get marine experts onboard to take photos and videos, and then come up with a more complete salvage plan once weather permits.

The Royal Dutch Shell drilling rig is carrying about 143,000 gallons of diesel fuel and about 12,000 gallons of lube oil and hydraulic fluid, according to federal on-scene response coordinator Capt. Paul Mehler.

Environmentalists have seized on the accident as proof Arctic Ocean oil operations are too risky. The drilling rig was being moved from its Arctic drilling grounds to Seattle for maintenance, and had passed through the Bering Sea and was set to cross the Gulf of Alaska when the storm hit.

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“Oil companies keep saying they can conquer the Arctic, but the Arctic keeps disagreeing with the oil companies,” Rep. Ed Markey, D-Mass., a member of the Natural Resources Committee, said in a statement.

A plan was being prepared in the event of a spill in the Partition Cove and Ocean Bay areas of the island. The area is home to at least two endangered species, as well as harbor seals, salmon, and sea lions.

Pa3 Jon Klingenberg / AP

This image provided by the U.S. Coast Guard shows the Royal Dutch Shell drilling rig Kulluk aground off a small island near Kodiak Island on Tuesday.

Mehler said a team of about 500 people was working on a plan, "with many more coming."

A Shell official said the drilling rig was built with a double-sided hull of reinforced steel that is 3 inches thick. It recently had undergone $292 million in improvements before being put into service for a short time this summer in the Beaufort Sea off Alaska's north coast.

It was being towed to Seattle for maintenance last week when it separated from a towing vessel south of Kodiak Island. Repeated attempts to maintain towing lines were unsuccessful as a severe storm passed through the area. By Monday night, tow boats guided the rig to a place where it would cause the least environmental damage and cut it loose.

Sean Churchfield, operations manager for Shell Alaska, said once the situation is under control, an investigation will be conducted into the cause. He did not know whether the findings would be made public.

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The Coast Guard said it also would investigate and make its findings public.

NBC News staff contributed to this report from The Associated Press.

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There were no immediate signs of a fuel spill from a storm-battered drilling rig that ran aground in Alaska on Monday, but environmentalists have seized on the accident as proof Arctic Ocean oil operations are too risky.

A nighttime Coast Guard helicopter flyover detected no sheen on the water off along the rocky coast of uninhabited Sitkalidak Island, just off the southeastern shore of Kodiak Island, said a spokeswoman for Shell, which owns the 28,000-ton Kulluk.

More flights during the day on Tuesday are needed to determine if the Kulluk spilled any of its 150,000 gallons of diesel fuel or caused other environmental problems.

The mishap late Monday, the culmination a high-seas drama that started unfolding last week, alarmed critics of Shell’s offshore drilling program in Alaska.

“Oil companies keep saying they can conquer the Arctic, but the Arctic keeps disagreeing with the oil companies,” Rep. Ed Markey, D-Mass., a member of the Natural Resources Committee, said in a statement.

In Arctic battle, Shell starts preliminary drilling

Lois Epstein, Arctic program director for The Wilderness Society, told Reuters that either the federal government or Shell should shut down the $4.5 billion drilling program “given the unacceptably high risks it poses to both humans and the environment.”

Shell officials said they were confident a spill would be avoided.

“The unique design of the Kulluk means the diesel fuel tanks are isolated in the center of the vessel and encased in very heavy steel,” Susan Childs, the oil giant’s on-scene coordinator, told The Associated Press.

“When the weather subsides and it is safe to do so, we will dispatch crews to the location and begin a complete assessment.”

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 The Kulluk, built in 1983 and given a $292 million upgrade for its Arctic mission, was being towed to Seattle for the off-season when the crisis began.

Shell’s towing ship, the Aiviq, lost its connection to the rig because of a busted shackle and then suffered engine failure. A Coast Guard cutter that raced to the rescue wound up with a broken propeller.

With extreme weather moving in, the Coast Guard evacuated all 18 of the Kulluk’s crew members on Saturday.

On Monday, the repaired Aiviq reconnected with the Kulluk and was towing it north when disaster struck again:  the line broke, leaving only a tug, the Alert, attached.

“Once the Aiviq lost its tow, we knew the Alert could not manage the Kulluk on its own, as far as towing,” Coast Guard Commander Shane Montoya said at a Monday night news conference.

Instead, the tug guided the Kulluk toward a low-impact spot and then disconnected with 30 minutes to spare before the inevitable grounding, to protect its own crew of nine.

With winds gusting to 70 mph and the seas cresting at 35 feet, the Kulluk then ran around about 9 p.m. Alaska time.

“We are now entering into the salvage and possible spill-response phase of this event,” Montoya said at a news conference a few hours later.

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ANCHORAGE, Alaska -- Confessed serial killer Israel Keyes admitted he enjoyed killing people, but couldn't or wouldn't give investigators a more meaningful answer when quizzed why he did it.

"There were just times, a couple of times, where we would try to get a why," said Anchorage Police officer Jeff Bell, who helped interrogate Keyes for hours.

"He would have this term, he would say, 'A lot of people ask why, and I would be, like, why not?'" Bell said.

Keyes confessed to killing eight people across the United States, but alluded to additional murders, FBI Special Agent Jolene Goeden and Bell told The Associated Press.

"Based on some of the things he told us, and some of the conversations we had with him, we believe the number is less than 12," Goeden said. "We don't know for sure. He's the only one who could have ultimately answered that."

They may never know the true number.

Keyes slit his wrist and strangled himself with bedding Sunday at the Anchorage Correctional Facility. He was facing a March trial on federal murder charges in the kidnapping and death of an 18-year-old Samantha Koenig, who was abducted from an Anchorage coffee stand Feb. 1.

He also wasn't going to stop. Authorities said he had weapons caches or body disposal kits stashed across the country.

One such disposal kit was found north of Anchorage. It included a shovel, plastic bags and bottles of Drano, which he told authorities would speed the decomposition of bodies.

A murder kit found in upstate New York had weapon parts, a silencer, ligatures, ammunition and garbage bags.

Keyes said other murder kits are hidden in Washington state, Wyoming, Texas and, investigators believe, somewhere in the Southwest, possibly Arizona.

Goeden and Bell conducted up to 40 hours of interviews with Keyes after his March arrest in Texas. During that time, Keyes confessed to killing Koenig, along with Bill and Lorraine Currier in Vermont, and five other people — although details for those victims were scarce.

The interviews also revealed Keyes' motivation, which was simple, Goeden and Bell said.

"He enjoyed it. He liked what he was doing," Goeden said. "He talked about getting a rush out of it, the adrenalin, the excitement out of it."

Keyes also liked seeing coverage of his crimes in the media, and he appeared to get a thrill out of talking about some of them with investigators, Goeden and Bell said.

His crimes started small with burglaries and thefts — until the urge escalated to murder.

Bell said Keyes told investigators the first violent crime he committed was a sexual assault in Oregon, in which he let the victim go.

"He planned on killing her but didn't," Bell said.

Keyes said the rape occurred sometime between 1996 and 1998 along the Deshutes River near Maupin, Ore., after he got the girl away from her friends. The girl was between the ages of 14 and 18, and would be in her late 20s or 30s now. No police reports were filed, and the FBI is seeking more information on the crime.

Of the five other murders Keyes confessed to, four were in Washington state and one occurred on the East Coast, with the body disposed of in New York.

In the case of the Curriers, authorities say Keyes flew from Alaska to Chicago on June 2, 2011, rented a car and drove almost 1,000 miles to Essex, Vt.

There, he carried out a "blitz" style attack on the Curriers' home, bound the couple and took them to an abandoned house. Bill Currier was shot, and his wife was sexually assaulted and strangled.

Keyes immediately returned to Alaska, and followed the case on his computer by monitoring Vermont media. The couple's bodies were never found after the house was demolished and taken to a landfill.

Leaving the area shortly after a murder was a familiar tactic for Keyes. After he abducted Koenig, he took her to a shed at his Anchorage home, sexually assaulted her and strangled her.

Keyes then left the next day for a two-week cruise, storing Koenig's body in the shed. Upon his return, he dismembered the body and disposed of it in a lake north of Anchorage. He was later arrested in Texas after using Koenig's debit card.

Koenig was his only known victim in Alaska. Goeden and Bell said he never explained why his broke his own rule of never killing anyone in the town where he lived because it's easier to be connected to such a killing.

The only mistake Keyes said he made was letting his rental car be photographed by an ATM when withdrawing money in Texas.

Unlike his earlier killings, the deaths of the Curriers and Koenig received a lot of news coverage.

"He was feeding off the media attention in the end," Bell said.

That wasn't the only change. His time between murders was growing shorter.

"He talked about that time period in between crimes, that over the last few years, that became quicker," Goeden said.

During their interviews, Keyes was willing to talk about the Koenig and Currier killings since he knew authorities had evidence against him.

"It was chilling to listen to him. He was clearly reliving it to a degree, and I think he enjoyed talking about it," Bell said of the Koenig and Currier deaths. But in the other cases, Keyes wasn't as forthcoming because he knew investigators had little on them.

Keyes, a construction contractor, told investigators that they knew him better than anyone, and that this was the first time he'd ever spoken about what he called his double life.

"A couple of times, he would kind of chuckle, tell us how weird it was to be talking about this," Bell said.

Even though he was talking to investigators, Keyes didn't want his name made public in any of the other investigations, especially the Curriers, because of the fallout of publicity. He threatened to withhold information if his name got out.

"If there was nobody else that he was concerned about, I think he wanted his story out there. He wanted people to know what he did," Goeden said. "What he was worried about is the impact that was going to have on the people that cared about him and were close to him."

Keyes will be buried Sunday in Washington state. 

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ANCHORAGE, Alaska — A security video showing the abduction of an Alaska barista is unnerving on its own, but it only hints at the horror ahead for the 18-year-old woman.

Samantha Koenig would soon be sexually assaulted and strangled after she was kidnapped from an Anchorage coffee stand, her body left in a shed for two weeks while her killer went on a cruise. After he returned, Israel Keyes photographed Koenig for a ransom note and then dismembered her body.

Those details were released by the FBI on Tuesday, two days after Keyes was found dead in his Anchorage jail cell in an apparent suicide. It's the most comprehensive account yet of a crime at the hands of a man who confessed to the slaying and told authorities he killed at least seven other people across the country over the past decade.

Serial killer found dead in Alaska jail cell, officials say

"These details are being provided both to fully explain the courage and resolve Samantha displayed in the final hours of her life, as well as in the hopes that the release of additional details will help investigations of other murders committed by Israel Keyes," the FBI said in a statement.

Once home from his trip, Keyes posed Koenig's body to make it appear she was still alive and took a Polaroid photo of her tied up, along with a newspaper dated Feb. 13 — 12 days after the abduction from a coffee stand, according to the FBI. Keyes later typed a ransom note demanding $30,000 from Koenig's family on the back of a photocopy of the photo and sent a text message to the woman's boyfriend on her cellphone with directions where he'd left the note at a local dog park.

Keyes dismembered Koenig's body and disposed of the remains in a frozen lake north of Anchorage after he cut a hole in the ice with a chain saw, authorities said.

Mark Thiessen / AP

During a news conference, police show surveillance video of Samantha Koenig, 18, making a cup of Americano coffee for a customer who shortly after abducted her Feb. 1, 2012, in Anchorage, Alaska. Police on Tuesday released the surveillance camera footage from the February abduction at the Common Grounds espresso stand in Anchorage.

Keyes, 34, was arrested in March in Texas, after using Koenig's stolen debit card at ATMs there and in Alaska, Arizona and New Mexico. He was facing a March trial in Koenig's death.

After his arrest, Keyes confessed to killing Koenig and at least seven other people. His other known victims were Bill and Lorraine Currier of Essex, Vt., who disappeared in June 2011. Keyes told authorities he also sexually assaulted and strangled Lorraine Currier.

Father of abducted barista, 18, pleads for her return

The couple's bodies have not been found.

Keyes did not identify the other victims or say where their remains were, other than that four were killed in Washington state and one was killed on the East Coast with the body disposed of in New York. Keyes had lived in Washington state and had property in upstate New York.

He told one of the lead FBI investigators in the case that his first victim was a teenage girl in Oregon that he sexually assaulted but did not kill, the Anchorage Daily News reported. FBI special agent Jolene Goeden told the newspaper that Keyes admitted that he was a teen at the time and that "he had the intention, he said, of killing her but but did not. And he did let her go."

Surveillance video
Also Tuesday, authorities released video footage of Keyes abducting Koenig, caught by a surveillance camera. Another video sequence shows him returning for Koenig's cellphone late that night, leaving Koenig bound in his truck, followed four minutes later by a man identified by the FBI as Koenig's boyfriend, who was looking for her. Keyes would use the cellphone to send text messages to the boyfriend and coffee stand owner that purported to be from Koenig saying she had a bad day and was leaving town for the weekend.

In the first video sequence, Keyes walks up to the small coffee stand and orders an Americano coffee, which Koenig makes. He then pulls out a gun and Koenig is then seen putting her hands up several times. At some point, Keyes makes her turn off the light. The light switch was close to a panic button, but Koenig never pushed it, probably because she was too afraid, police said.

Keyes then climbs into the kiosk and, police said, used zip ties to bind Koenig's hands behind her back before leading her out. He told Koenig he would let her go if her family paid a ransom, but that was never his intention, police said.

Body in icy lake is missing Alaska barista, police say

"He knew all along he was going to kill her," Anchorage homicide Detective Monique Doll said.

Police said Keyes removed the battery from Koenig's cellphone to avoid being tracked.

Koenig's body was recovered from the lake in April after Keyes told authorities of its location.

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ANCHORAGE, Alaska - A powerful earthquake rocked one of the few inhabited islands in Alaska's Aleutian chain on Wednesday, but no damage has been found, federal and local officials said.

The magnitude 6.9 quake, centered 80 miles southwest of Adak, struck at 3:40 p.m. local time (7.40 p.m. ET), the West Coast and Alaska Tsunami Warning Center said. No tsunami warning was issued, but scientists will monitor the area for any possible earthquake-related waves, center Director Paul Whitmore said.

In Adak, a community of about 330, "We definitely felt it," City Manager Layton Lockett said.

The building that houses city offices and the local school, engineered to withstand frequent earthquakes that strike the region, performed as designed, Lockett said.

"You could just hear the building move, and things were shaking," he said.

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No damage was found, though officials were concerned about the fate of underground pipes, he said. The school, which has about 20 students, was out of session at the time.

Adak, an island city about 1,300 miles southwest of Anchorage, is a converted U.S. Navy station that once housed 6,000 people. It now operates as a port and seafood-processing center serving the North Pacific commercial fishing fleet.

Other moderate earthquakes have struck western Alaska in recent days, according to the center.

A magnitude 4.9 quake was recorded 90 miles west of the Alaska Peninsula town of Cold Bay on Tuesday. A magnitude 5.2 quake about 90 miles southwest of Kodiak was recorded on Sept. 18.

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Shell

Shell's Noble Discoverer drilling rig sits above an oil field in Alaska's Chukchi Sea on Saturday, Sept. 8.

More than 20 years after the last drill bit went into the Chukchi Sea floor off northern Alaska, a Shell drilling rig on Sunday began work that the company hopes will lead to a bonanza that adds to its bottom line and extends Alaska's oil economy.

"Today marks the culmination of Shell’s six-year effort to explore for potentially significant oil and gas reserves, which are believed to lie under Alaska’s Outer Continental Shelf," Shell Alaska Vice President Pete Slaiby said in a statement.

Welcomed by the Obama administration, the exploration in Alaska's Arctic waters has become a major battleground for environmental groups, which fear oil spills in the pristine area already threatened by warming temperatures and reduced sea ice.

"The melting Arctic is a dire warning, not an invitation to make a quick buck," said Dan Howells, a campaign director for Greenpeace.

Shell has paid the U.S. $2.8 billion for lease rights to areas in the Chukchi and neighboring Beaufort Sea, and the U.S. estimates those waters hold 26 billion barrels of recoverable oil and 130 trillion cubic feet of natural gas.

On Aug. 30, Interior Secretary Ken Salazar announced that Shell, even though its spill response barge was not yet certified by the Coast Guard, would be permitted to drill pilot holes and then dig what's called a cellar to hold a critical safety device.

The pilot holes will be 1,300 feet below the ocean floor and roughly 4,000 feet above a known petroleum reservoir. 

Shell argues there's little chance of a spill like BP's 2010 Gulf of Mexico disaster. Drilling will be in water about 130 feet deep, it says, versus 5,000 at the site of the gulf spill, and wellhead pressure is expected to be far less.

Support vessels could quickly choke off and cleanup any spill, Shell adds. 

Workers on Friday moored the drill ship, the Noble Discoverer, in heavy seas with eight anchors that each weigh 15 tons. The diameter of the circular pattern of anchors is more than 6,500-feet, it added.

The immediate goal is to dig a 20-by-40-foot mud-line cellar that will house a blowout preventer below the seafloor, protecting it from ice scraping the bottom.

Shell's oil spill response barge remains in Bellingham, Wash., and is expected to undergo sea trials over the weekend, Shell said.

Shell

This illustration shows how far drilling will go for now, as well as what the cellar for the blowout preventer will look like.

Shell last explored in the area in 1991, but it was not economically viable to produce from there at the time.

Shell's other Arctic Ocean drill ship, the Kulluk, is in the Beaufort Sea waiting for the fall whale hunt to end before moving to the drill site.

The company isn't expecting to drill for oil until next year, since it only has a few weeks before sea ice forms in the area. It will then resume drilling next summer.

The Associated Press contributed to this report.

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ANCHORAGE, Alaska -- Seventy-six people were rescued on Sunday from a sightseeing vessel that ran aground in Alaska's Glacier Bay and began filling with water, the U.S. Coast Guard said.

None of the passengers and crew members aboard the 79-foot Baranof Wind was seriously hurt, though some minor injuries were reported, Coast Guard Petty Officer David Mosley said.

The Coast Guard, National Park Service and a civilian cruise ship assisted in the Baranof Wind's evacuation, the Coast Guard said in a statement.

Most of the passengers were safely transferred to a large Holland America cruise ship, the Vollendam, which was in the area and responded to the emergency, and two people were taken aboard a National Park Service vessel, the Coast Guard said.

A Coast Guard cutter and helicopter also were dispatched to the scene.

Four crew members from the Baranof Wind remained aboard the tour boat and worked with Coast Guard personnel to pump water out of the vessel and keep it from sinking, the Coast Guard said. The boat was stabilized after the accident, and there were no immediate signs of spills or other pollution, Mosley said.

The boat's owner was arranging to tow the vessel into port, he said. The Alaska Dispatch newspaper reported that the vessel was headed toward Sitka.

Alaska issues permit for work on Gold-Rush era shipwreck

The accident was reported to the Coast Guard at about 11 a.m. local time (1 p.m. ET) and it has begun an investigation, Mosley said.

Glacier Bay, at the northern end of southeastern Alaska's Inside Passage, is a major tourist destination known for its spectacular scenery and marine life.

Reuters contributed to this report.

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ANCHORAGE, Alaska -- A hiker has died after falling into a river in a remote part of northern Alaska,  the U.S. Coast Guard said Thursday. His companion was rescued by helicopter.

The Coast Guard did not release the identity or nationality of the victim, who slipped off a cliff in the Brooks Range on Wednesday night. The companion, Olaf Schooll of Norway, was rescued, the Coast Guard said in a statement.

The two men had been trying to hike across the northern part of Alaska, from the Canadian border to the Bering Sea, the statement said.

The accident occurred at Atigun Gorge, a spot about 240 miles southeast of Barrow, it said.

Schooll used a satellite telephone to call for help, the statement said. A Coast Guard air crew found him, hoisted him into a helicopter and flew him to Barrow.

More Alaska coverage from NBC station KTUU in Anchorage

Crew members found his dead companion about a mile downstream in the Atigun River, but terrain and water conditions prevented the recovery of the man's body at that time, the Coast Guard said. Searchers were attempting on Thursday to recover the body.

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FlyDrake.com via Glacier Bay National Park

Rock and debris from a landslide lie along five miles of what had been an ice-white glacier inside Glacier Bay National Park.

A massive landslide sent tons of rock and debris tumbling more than five miles down a glacier in Alaska, the National Park Service reported in an event that could be yet another sign of a warming world.

Located in a remote area of Glacier Bay National Park, the slide was so big it registered on earthquake monitors as a magnitude 3.4 event.

Officials noticed the monitor blip on June 11 but it wasn't until July 2 that a pilot passing over the site took photos that showed just how large it was, Glacier Bay National Park announced on its Facebook page.

"It's certainly the largest that we're aware of" inside the park, Glacier Bay ecologist Lewis Sharman told msnbc.com.

Larger landslides have happened over geologic time, Marten Geertsema, a natural hazards researcher for the Forest Service in nearby British Columbia, told msnbc.com, but it definitely was "one of the longest runout landslides on a glacier in Alaska and Canada in recent times."

Moreover, the force was enormous, Geertsema said. No one was present, but had anyone been there they probably "would be blown over by the air blast," he told the Associated Press. 

Officials ruled out an earthquake as the trigger that caused part of the nearly 12,000-foot Lituya Mountain to give way, smothering the ice-white Johns Hopkins Glacier with dark rock and debris over an area a half-mile wide and 5.5 miles long.

Drake Olson / FlyDrake.com via AP

The landslide is viewed from above the Johns Hopkins Glacier.

One possibility is that thawing permafrost, which is ground that stays frozen for two more our years, caused the slide.

"We are seeing an increase in rock slides in mountain areas throughout the world because of permafrost degradation," said Geertsema. 

"I don't know whether permafrost degradation played a role here, but we can be almost certain that permafrost exists on Lituya Mountain," said Geertsema, who reviewed aerial photos of the mountain and slide area. "Certainly this type of event could happen from permafrost degradation."

Many areas of mountain permafrost have been thawing in recent decades as temperatures warm, and some experts are becoming convinced that thawing is a factor in the frequency of rock slides, Geertsema said, pointing to data by Swiss scientists studying the Alps.

Marten Geertsema and Drake Olson

The section of rock and ice that slid off Lituya Mountain is seen here. Marten Geertsema estimates it was 200 meters, or about 600 feet, wide.

"It plays an important role," Geertsema said of climate change. "I think we have been underestimating the role it might play." 

Sharman, the park ecologist, echoed that sentiment, saying he's heard from experts that "they would not be surprised" to see more such landslides inside the national park if temperatures continue to warm.

"Certainly we are seeing an increase in large landslides over the past decades," Geertsema said, citing his 2006 study that found between 1973 and 2003 the average in northern British Columbia increased from 1.3 large landslides per year to 2.3.

Moreover, he said, most of the slides in northern British Columbia are happening in the warmest years.

Landslides like this one can also be triggered by other factors, Geertsema added, such as a combination of large snowpack and a cold spring that results in a delayed and then rapid melt.

The slide itself was miles from areas used by park visitors, most of whom see Glacier Bay by cruise ship. 

"You can't see it from a boat or the bay. You've got to be up flying. And it's not on a typical flying route," park service spokesman John Quinley told Reuters. "It would have been pretty horrific if you'd been camped on the glacier."

And it won't reach the bay for a long time.

"The landslide is approximately 12-14 miles up the glacier," the park said on its Facebook page, and the glacier itself moves material towards the bay only about 10-15 feet a day. "So this debris may not reach the face of the glacier for many years," it added.

Officials are currently trying to estimate the volume of material that fell in the slide.

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In 1958, a nearby landslide, this one above Lituya Bay and triggered by a 7.7 earthquake, created a wave hundreds of feet high that washed 1,720 feet up a narrow inlet. Two people on a fishing boat vanished and three others on land were killed. 

One fishing vessel was able to ride out the wave, Geertsema noted.

"They looked below them and they could see the tops of the Sitka spruce trees way below," he said. "The other boat disappeared."

Last month's slide covered more land area than the 1958 incident, but even so it probably won't go down as the biggest one by volume in North America.

"We do not know the volume of the recent landslide on the Johns Hopkins Glacier yet, but it is unlikely to break the volume record," Rex Baum, a U.S. Geological Survey expert, told msnbc.com.

What is the record? That, said Baum, would be the 2.8 cubic kilometer rock slide avalanche from the May 18, 1980, eruption of Mount St. Helens in Washington state.  

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