OAKLAND, Calif. (KTVU) -- At least 13 workers were hurt Friday when part of the second floor of a building in Oakland collapsed, temporarily trapping the employees in wet concrete, authorities said.
No major injuries were reported, said Oakland Fire Battalion Chief Ian McWhorter although the workers suffered minor cuts, scrapes and bruises, he said.
Officials said 12 workers were rushed to a local hospital for medical treatment after the incident, which occurred when the workers were pouring wet concrete from the second floor at the building at Hawthorne Avenue near Broadway.
Firefighters were called to help at 9:40 a.m. after workers called to say they were trapped in the wet concrete and some were hanging from scaffolding, he said. Some workers were able to get out on their own, he said.
When firefighters arrived on the scene, workers were already rescuing other workers.
McWhorter said the workers were trapped up to their knees in concrete. Part of the second floor collapsed during the concrete pour. Cal/OSHA is now investigating the incident, authorities said.
"It all happened at once," said construction worker Jonathan Davis. "I'm still shaking. But I'm happy to be alive."
"We don't know exactly what caused this incident to occur," McWhorter said.
The site, 3093 Broadway, is the former Bay City Chevy dealership and is poised to become an apartment and retail space.
The area is near a neighborhood nicknamed "Pill Hill," because of all the doctor's offices, and Sprouts, a new grocery store.
Contractor Johnstone Moyer, based in San Carlos, has had 11 mostly minor cases investigated by Cal-OSHA in the last four years, records show. They mostly related to permit problems.
The incident prompted officials to close part of Broadway while regulators investigated the crash.
KTVU reporter Tom Vacar contributed to this report.