Sinkhole a deadly reminder of Florida's unstable land mass

It started with a crash. Screams. Then nothing.

The earth that opened up beneath Jeffrey Bush's bedroom and swallowed him on Friday was a terrifyingly rare reminder of the unpredictable dangers just below Florida's surface.

The sinkhole, estimated at 6 metres wide and 6 metres deep, caused the concrete floor of the home to cave in as everyone in the Tampa-area house was turning in for the night.

Engineers resumed their work at the sinkhole yesterday to do more tests on the dangerous ground. Authorities also evacuated surrounding homes.

Engineers said they may have to demolish the small, sky-blue house, even though from the outside there appeared to be nothing wrong with the four-bedroom, concrete-wall structure, built in 1974.

Central Florida - particularly the Interstate 4 corridor from Volusia County to Hillsborough County - is more susceptible to sinkholes than the rest of the state because of its geology.

Sinkholes form when water dissolves limestone, causing sands to migrate through and form a hole on the surface - like the neck of an hourglass.

"It's like pulling the plug on a drain and swoosh, everything circles down the hole," said Mike Perkins, of the Orange County History Centre's sinkhole exhibit. "This is almost like an earthquake; it just happens."

The region has a history of sinkhole activity. Three years ago, sinkholes collapsed lanes of US Highway 27 in east Polk County.

But experts could not recall the last time they heard about a loss of life related to a sinkhole.

Hillsborough Fire Rescue officials lowered a camera and listening device into the hole to try to find Jeffrey Bush. But the ground kept moving and they lost the equipment.

"He's down there, but we can't hear anything and we can't see anything," said Ronnie Rivera, a Hillsborough County Fire Rescue spokesman. "We just can't do anything."

The victim's brother, Jeremy, said: "I know in my heart he's dead."

Six people were at home at the time of the incident, including Jeremy's wife and his two-year-old daughter. The brothers were maintenance workers, including picking up trash along highways.

Jeremy Bush said he heard a crash and the screams of his 36-year-old brother late on Thursday. Running to help, all he could see was his brother's mattress sticking up out of the centre of a large, dark sinkhole threatening to take the entire house into the depths.

"I thought I could hear him hollering for me to help him," Bush said. He said he jumped into the collapsing hole hoping to save his brother and used a shovel to dig. But Hillsborough County deputies pulled him out before he was sucked in farther.

County administrator Mike Merrill described the home as "seriously unstable". He said no one could go in the home because officials were afraid of another collapse and losing more lives. The soil around the home was very soft and the sinkhole was expected to grow.

A sinkhole near Orlando grew to 122 metres across in 1981 and devoured five sports cars, most of two businesses, a three-bedroom house and the deep end of an Olympic-size swimming pool.

Jeremy Bush said someone came to the house recently to check for sinkholes, apparently for insurance purposes. "He said there was nothing wrong with the house. Nothing. And a couple of months later, my brother dies. In a sinkhole," he said.

McClatchy Tribune, Associated Press