About 30 percent of the three-story structure collapsed around 3 a.m. Monday, Lake County Fire Rescue Battalion Chief Tony Cuellar said. The villa at the Summer Bay Resort had already been evacuated and no injuries were reported.
Cuellar said authorities were also concerned about another section of the villa, which was sinking.
The sinkhole, which is in the middle of the villa, is about 40 to 50 feet in diameter, Cuellar said. He said authorities think it was getting deeper but couldn't tell early Monday if it was growing outward.
The villa houses 24 units and about 20 people were staying in it at the time, Cuellar said.
Authorities were called to the scene, about 10 miles west of Disney World, late Sunday where they found that the building was making popping sounds and windows were breaking.
A nearby villa was also evacuated as a precaution, Cuellar said.
Cuellar said there was a gas leak but the gas has since been shut off.
Witnesses told The Associated Press they could hear a cracking sound as the villa began sinking. A large crack was visible at the building's base.
Luis Perez, who was staying at a villa near the sinking one, said he was in his room when the lights went off around 11:30 p.m. He said he was on his way to the front desk to report the outage when he saw firefighters and police outside.
"I started walking toward where they were at and you could see the building leaning and you could see a big crack at the base of the building," said Perez, 54, of Berona, N.J.
Associated Press writer Bernard McGhee in Atlanta contributed to this report.
Copyright 2013 The Associated Press.