Jeffrey Bush, 36, is presumed dead after rescue crews failed to make contact with him.
Officials in the town near Tampa have postponed further rescue efforts until they determine how much of the ground under the house is compromised.
Sinkholes are common in certain parts of Florida, Hillsborough County's fire chief said.
"Florida essentially sits on a system of caverns," Chief Ron Rogers said, saying water erosion in the caverns causes them to collapse and sinkholes to form on the surface.
The sinkhole is about 20 feet to 30 feet across and may be 30 feet deep, said Bill Bracken, president of an engineering company assisting emergency workers. The hole was originally reported to be 100 feet across, but that is the diameter of the safety zone surrounding it, Bracken said.
Jeffrey Bush's brother Jeremy told rescue crews he heard a loud crash near midnight on Thursday, then his brother screaming for help.
He said he jumped into the hole but couldn't see his brother.
All Jeremy Bush can do is wait -- wait for word that Florida authorities have recovered the body of his brother from a sinkhole that opened beneath the bedroom of the family's suburban Tampa home.
The effort to recover the body of Jeff Bush was scheduled to resume Saturday morning at 7 a.m. ET after authorities stopped operations overnight, saying the hole is still expanding and the house could collapse at any time.
Voice of Russia, BBC, CNN