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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