Rescue crews have ended their search for the body of a Florida man who is believed to have died after a sinkhole formed beneath his bedroom two days ago.

Hillsborough County Administrator Mike Merrill confirmed Saturday that the search for Jeff Bush’s body is over, and said crews will begin demolishing the home on Sunday.

"At this point it's really not possible to recover the body," Merrill said. He later added that, "we're dealing with a very unusual sinkhole.”

Bush, 37, is feared dead after the sinkhole, estimated at 20 feet across and 20 feet deep, caused the home's concrete floor to cave in underneath his bedroom at around 11 p.m. Thursday.

Five other people were in the house in Seffner, about 24 kilometres east of Tampa, at the time but managed to escape unharmed.

Bush's brother Jeremy jumped into the hole to try to help, but he had to be rescued himself by a sheriff's deputy.

Earlier Saturday, engineers probing the sinkhole warned that the entire house could succumb to the shifting ground.

Authorities evacuated two nearby homes and warned that more evacuations could take place as the sinkhole slowly expands.

The family that lived next door to the Bush home were ordered out of their house on Friday, but were allowed back in for half-an-hour Saturday to pack up some of their belongings.

Other neighbours feared their own homes were susceptible to a sinkhole.

"I've had nightmares," said Soliris Gonzalez, 31. "In my dreams, I keep checking for cracks in the house." Gonzalez said her family has moved important documents to a storage facility.

Experts say the underground of West Central Florida looks similar to Swiss cheese, and the geography lends itself to sinkholes.

As engineers continued their probe, media crews were moved further away from the Bush house so experts could perform tests on the home across the street.

Officials said the entire property is dangerous and no one has been allowed into the home.

"I cannot tell you why it has not collapsed yet," engineer Bill Bracken said, adding that the earth below the home was a "very large, very fluid mass."

Sinkholes are very common in Florida, with more than 500 reported in Hillsborough County alone since 1954. The state is prone to sinkholes because of caverns of limestone below the ground, which easily dissolve in water.

Because sinkholes are so common, a state law requires home insurers to provide coverage against them.

However, while past sinkholes have swallowed up cars, homes, swimming pools and other buildings, it’s extremely rare for a person to be swallowed by one.

Jeremy Bush was about to enter the room around 11 p.m. on Thursday when the floor opened, taking Jeff, along with all the furniture.

"I went in my bedroom, heard a loud crash, ran in that direction," Jeremy said. "I was getting ready to run into the room and I almost fell into the hole. I jumped into the hole and started digging. I started screaming for him."

However, Jeremy could not see his brother and was eventually pulled out of the 10-metre hole by police.

Jeremy said someone had come to the home a few months ago to check for sinkholes 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.

Officials said Saturday that a fund had been set up to help the families affected by the sinkhole.

With files from The Associated Press