SEFFNER, Fla. (AP) -- Engineers worked gingerly Saturday to find out more about a slowly growing sinkhole that swallowed a Florida man in his bedroom, believing the entire house could eventually succumb to the unstable ground.
It could be days before officials decide whether they will attempt to recover Jeff Bush's body, and they were still trying Saturday to determine the extent of the sinkhole network and what kind of work might be safe. As the sinkhole grows, it may pose further risk to the subdivision and its homes.
Bush, 37, was in his bedroom Thursday night in Seffner -- a suburb of 8,000 people 15 miles east of downtown Tampa -- when the earth opened and took him and everything else in his room. Five others in the house escape unharmed.
On Saturday, the normally quiet neighborhood of concrete block homes painted in Florida pastels was jammed with cars as engineers, reporters, and curious onlookers came to the scene.
At the home next door to the Bushes, a family cried and organized boxes. Testing determined that their house also was compromised by the sinkhole, according to Hillsborough County Fire Rescue spokesman Ronnie Rivera. The family, which had evacuated Friday, was allowed to go inside for about a half-hour to gathering belongings.
Sisters Soliris and Elbairis Gonzalez, who live on the same street as Bushes, said rumors are swirling among neighbors, with people concerned for their safety.
"I've had nightmares," Soliris Gonzalez, 31, said. "In my dreams, I keep checking for cracks in the house."
They said the family has discussed where to go if forced to evacuate, and they've taken their important documents to a storage unit.
"The rest of it, this is material stuff, as long as our family is fine," Soliris Gonzalez said.
"You never know underneath the ground what's happening," added Elbairis Gonzalez, 30.
Experts say thousands of sinkholes erupt yearly in Florida because of the state's unique geography, though most are small and deaths rarely occur.
"There's hardly a place in Florida that's immune to sinkholes," said Sandy Nettles, who owns a geology consulting company in the Tampa area. "There's no way of ever predicting where a sinkhole is going to occur."
Most sinkholes are small, like one found Saturday morning in Largo, 35 miles away from Seffner. The Largo sinkhole, at about 10 feet long and several feet wide, is in a mall parking lot. Such discoveries are common throughout the year in Florida.
The state is prone because it sits on limestone, a porous rock that easily dissolves in water, with a layer of clay on top. The clay is thicker in some locations -- including the area where Bush became a victim -- making them even more prone to sinkholes.
Jonathan Arthur, the state geologist and director of the Florida Geological Survey, said other states sit atop limestone in a similar way, but Florida has additional factors -- extreme weather, development, aquifer pumping and construction -- that can cause sinkholes. "The conditions under which a sinkhole will form can be very rapid, or they can form slowly over time," he said.
But it remained unclear Saturday what, if anything, caused the Seffner sinkhole.
"The condition that caused that sinkhole could have started a million years ago," Nettles said.
Engineers had been testing in the area of the Bush house since 7 a.m. Saturday. By 10 a.m., officials moved media crews farther away so experts could test a home across the street.
Experts spent the previous day on the property, taking soil samples and running tests -- while acknowledging that the entire lot where Bush lay entombed was dangerous. On Saturday, officials were still not allowing anyone in the Bush home.
Jeremy Bush, who tried to rescue his brother when the earth opened, lay flowers and a stuffed lamb near the house Saturday morning and wept.
He said someone came to his home in the Tampa suburb of about 8,000 people a couple of months ago to check for sinkholes and other issues, apparently for insurance purposes, but found nothing wrong. State law requires home insurers to provide coverage against sinkholes.
"And a couple of months later, my brother dies. In a sinkhole," Bush said Friday.
The sinkhole, estimated at 20 feet across and 20 feet deep, caused the home's concrete floor to cave in around 11 p.m. Thursday as everyone in the Tampa-area house was turning in for the night. It gave way with a loud crash that sounded like a car hitting the house and brought Jeremy Bush running.
Engineers said they may have to demolish the small house, even though from the outside there appeared to be nothing wrong with the four-bedroom, concrete-wall structure, built in 1974.
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