WASHINGTON — A man is presumed dead after a sinkhole opened up under his bedroom in the US state of Florida and "swallowed" him, CNN reported Friday.

The incident happened overnight in Brandon, a suburb of Tampa. Authorities called to the scene found the hole to be about 100 feet (30 meters) in diameter and were unable to make contact with the victim.

His 36-year-old's brother heard screams and tried in vain to pull him out.

"There is no evidence of him being alive," CNN quoted Jessica Damico, a spokeswoman for the Hillsborough County Fire Department, as saying.

She was quoted as saying the hole was still actively developing and was not man made.

Authorities have evacuated the neighborhood as a precautionary measure.