Three levels of slab cement collapsed in a pancake effect inside the steel superstructure of a multistory parking garage being built at the Fontainebleau-Las Vegas, Clark County fire spokesman Scott Allison said.

"Nobody is hurt everyone is accounted for," Allison said after a head count of workers.

Residents in neighboring high-rise condominiums reported hearing a rumble, feeling the ground shake and seeing a cloud of dust rise from the collapse, which was reported at 10:24 a.m.

It was the second mishap in less than a week at the Fontainebleau site, where one worker died and two workers were hurt after falling Thursday morning from atop a 30-foot wall.

Nevada Occupational Safety and Health Enforcement is investigating that accident.

Allison said work on the parking structure was suspended Monday and the area was roped off pending an investigation of why a floor gave way. He said work was continuing on the neighboring Fontainebleau high-rise tower.