A sinkhole that swallowed a man in Florida when it opened up in his bedroom is "seriously unstable" and likely to grow, officials have warned.
No one is being allowed inside the home where Jeff Bush is thought to have died, because authorities fear more lives could be lost.
Hillsborough County administrator Mike Merrill described the hole as "seriously unstable" after engineers said the soil around the house was very soft and could suffer another collapse.
He said: "This is no ordinary sinkhole. This is a chasm."
Five other people were at the home when the bedroom floor began to fall through into the 15m-deep hole on Friday, but no one else was injured.
Hillsborough County Fire Rescue officials said the 37-year-old missing man was now presumed to have died.
The victim's brother, Jeremy Bush, said he jumped into the hole but could not see his brother and had to be rescued by a sheriff's deputy who 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," he said.
"But I just couldn't do nothing. I could swear I heard him hollering my name to help him.
"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."
Florida is highly prone to sinkholes because of underground limestone, a porous rock that easily erodes in water - leading to collapse.
Sinkholes are so common in Florida that state law requires home insurers provide coverage against the danger.
Mr Bush said someone visited 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," he said.