Sinkholes are becoming common in Florida where sandy soil sits on top of layers of clay and limestone. NBC's Janet Shamlian reports.
Another large sinkhole has formed in Florida, causing parts of two homes to collapse and swallowing a boat and a backyard pool.
The sinkhole in Dunedin, Fla., erupted early Thursday morning between the two houses, and by noon, had grown to a size of about 70 feet wide by 53 feet deep.
"There was apparently some work being done to try to fill in what they thought was a sinkhole beneath the house the last couple of days," Dunedin Fire Chief Jeff Parks said. "The owner woke up this morning at 5:40 when he heard noises on his back porch and went out and found the sinkhole at that point."
Conestoga-Rovers and Associates, an engineering and environmental consulting company, confirmed it had been at the home earlier this week.
Luke Johnson / Pool via Getty Images
The rear portion of a home is consumed by a sinkhole on Thursday, Nov. 14 in Dunedin, Fla.
A screened-in porch and a 14-foot-long boat at the homeowner's property had collapsed into the hole, and next door, the master bedroom and a swimming pool had gone in. The garage at the second home was also starting to crumble by late morning, Parks said.
City officials condemned both homes. There were no injuries, Parks said.
Six houses in Dunedin — a city on central Florida's west coast — were evacuated, and power and utility lines were cut after officials arrived. The engineering company that was working on the house earlier in the week was also on the scene, waiting for the ground around the sinkhole to be stable enough for them to work to fill it.
After opening up early in the morning, a growing sinkhole has swallowed most of a swimming pool, and damaged two homes, forcing evacuation of Florida neighborhood. WFLA's Judd Chapin reports.
"They thought it would slow down to the point where it would stop, but in the last half hour, it's still continued to grow," Parks said. "They're just assessing right now to see what they can do."
Sinkholes are relatively common in Florida, but do not always cause major disruption or injuries. In February, a Seffner, Fla., man was killed when a massive sinkhole opened up underneath his family's home.
Engineers had been pouring grout into the house's foundation for the past two days, Michael Dupre told BayNews9.com in Florida.
"There was a sinkhole before and we knew there was sinkhole activity," Dupre told BayNews9.com. "After the Seffner sinkhole, we were scared. We've been dealing with our insurance company and finally two days ago, they started working on our house. Now it looks like our home is gone."
John Marquardt, a geotechnical engineer with Conestoga-Rovers and Associates, said the work being done this week was a continuation of a project that was started two years ago.
"The homeowner had filed a claim with their insurance company alleging damage due to sinkhole activity," he said.
The engineers diagnosed the "sinkhole activity" — movement under the ground — at the site two years ago, but did not see any actual sinkholes at the time. Sinkhole activity is not always a precursor to sinkholes, and could not have led engineers to know that Thursday's sinkhole was going to occur, Marquardt said.
The work the engineers were doing earlier this week may have had a slight effect on the timing of the sinkhole, he said.
"Any time you start changing the subsurface, if there's anything that's going to collapse, you can trigger it," he said. "It may have occurred before we got there, it may have occurred a day after we got there, no matter what. It may have occurred next week if we hadn't doing anything. Either way, it was going to happen."
The sinkhole is still growing because the "upper soils [are] caving off the sides," he said, and that could continue for the next few days.
"We're not doing anything right now for a couple of reasons," he said. "We want to wait and let it become stable and the insurance company has to make a decision as to whether they're going to call it a total loss."
Luis Echeverria / AP
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This story was originally published on Thu Nov 14, 2013 7:49 PM EST