The first portions of the building to sink were the walkways and the elevator shaft, Gade said.
“You could see the ground falling away from the building where the building started leaning,” Gade said. “People were in shock to see a structure of that size just sink into the ground slowly. ... You could see the stress fractures up the side of the structure getting wider.”
Then, as part of the leaning building crumbled quickly into the ground, dust shot up around the site.
In one of the adjacent buildings, firefighters and police officers knocking on doors woke up Maggie Moreno of San Antonio. She couldn’t get the door to her unit open all the way.
“It sounded like popcorn,” said Moreno, who was visiting with her husband, daughter and two grandchildren. “The building was just snapping.”
Luis Perez also was staying at a nearby building. He 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 it 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 New Jersey.
Over the next five hours, sections of the building sank into the ground. Paul Caldwell, the development’s president, said the resort gave all affected guests other rooms. Some visitors — many of whom had to leave their wallets, purses and other belongings behind in the quick evacuation — were given cash advances by Summer Bay.
There were no signs before Sunday that a sinkhole was developing, Caldwell said. He said the resort underwent geological testing when it was built about 15 years ago, showing the ground to be stable.