Paul Caldwell, general manager of the 64-acre, lake-side resort, said the building collapsed almost entirely within 45 minutes, leaving only the top floor visible from the ground.

Shanley, whom Caldwell hailed as “a hero,” said he saw balconies breaking. He went into the building, through all the floors, banging on doors, using his master key to open doors and wake people to get them out.

While he was on the second floor, he felt the building sink about 20 inches and saw the ceilings collapsing.

He continued on to the third floor to help get all the guests safely out. By the time he was on the third floor, the entire third-floor ceiling had collapsed, he said.

Shanley kept going until the fire department came and made him leave.

Asked if he felt his life was ever at risk, Shanley said, “Yes ma'am, but I didn't think of that at the time. I was more concerned about my guests and trying to get them out of here.”

A total of 36 people were evacuated, including 20 from the collapsed building and another 16 from a building evacuated as a precaution, according to the resort's executive vice president, Juan Barrillas.

Caldwell praised Shanley for not waiting for authorization before starting the evacuation.

“Had he not acted on his own we are confident there could have been many people trapped in that building,” said Caldwell.

Sinkholes in Florida are relatively common, caused by the state's porous geological bedrock of limestone. As acidic rainwater filters into the ground, it dissolves the rock, causing erosion that can lead to underground caverns, resulting in the collapsing sinkholes.

“One woman was sitting in the tub and the tub levitated, and that's when she just grabbed a pair of shorts and came out,” resort guest Maggie Ghamry told WFTV. She said another couple with an infant baby had to smash through a room window after the door frame collapsed.

The collapsed building had two wings of 12 units each, connected by an elevator tower in the breezeway.

Julian and Maggie Moreno of San Antonio, Texas, were staying in a two-bedroom suite opposite the collapsed building with their daughter and two grandchildren when they heard police in the hall yelling for everyone to “grab stuff and get out.”

Julian Moreno tossed suitcases off a third-floor balcony. As they left the suite their door was already jamming, leading them to believe their building was sinking, too.

The resort relocated guests to other units on the property, the Morenos said, but the family put off a trip to Disney World. “We're just trying to figure out how to feed the kids and get this settled,” he said.

Dembley said several dozen evacuated guests were being housed in other buildings on the property, about six miles from Walt Disney World.

In March a sinkhole opened under a Tampa area home, swallowing the bedroom of 37-year-old landscaper Jeff Bush, whose body was never recovered.

In 1981 in Winter Park near Orlando, a sinkhole measuring 320 feet wide (98 meters) and 90 feet deep swallowed a two-story house, part of a Porsche dealership, and an Olympic-size swimming pool. The site is now an artificial lake in the city. (Editing by David Adams, Jeffrey Benkoe and Leslie Adler)