Engineers are to conduct further tests after a Florida sinkhole swallowed a man in his bedroom.
They have already determined that the soil in the slowly growing sinkhole around the home is very soft and believe the entire house could eventually be devoured.
Jeff Bush, 37, is presumed dead after the earth opened under his bedroom, swallowing him.
About the only thing left was the TV cable running down into the hole.
Sinkholes are a hazard so common in Florida that state law requires home insurers to provide coverage against the danger.
The sinkhole, estimated at 6m across and 6m deep, caused the home's concrete floor to cave in on Thursday.
It gave way with a loud crash that sounded like a car hitting the house and brought Mr Bush's brother running.
Jeremy Bush said he jumped into the hole but couldn't see his brother and had to be rescued himself by a sheriff's deputy who reached out and pulled him to safety as the ground crumbled around him.
"The floor was still giving in and the dirt was still going down, but I didn't care. I wanted to save my brother," Jeremy Bush said. "But I just couldn't do nothing."
He added: "I could swear I heard him hollering my name to help him."
Officials lowered equipment into the sinkhole and saw no signs of life, said Hillsborough County Fire Rescue spokeswoman Jessica Damico.
A dresser and the TV set had vanished down the hole, along with most of Bush's bed.
"All I could see was the cable wire running from the TV going down into the hole. I saw a corner of the bed and a corner of the box spring and the frame of the bed," Jeremy Bush said.
At a news conference last night, county administrator Mike Merrill described the home as "seriously unstable."
He said no one can 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.
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.
Florida is highly prone to sinkholes because there are caverns below ground of limestone, a porous rock that easily dissolves in water.
A sinkhole near Orlando grew to 122m 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.
More than 500 sinkholes have been reported in Hillsborough County alone since the government started keeping track in 1954, according to the state's environmental agency.
Jeremy Bush said someone came out to the home a couple of months ago to check for sinkholes and other things, 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," Mr Bush said.
Six people were at the home at the time, including Jeremy Bush's wife and his two-year-old daughter.