It was a routine Friday morning on a large construction site far from New York City. Workers were pouring concrete when suddenly the routine turned into the very unusual.

The floor the concrete was being poured into collapsed in a construction accident in Cincinnati. Thirteen people were injured; one worker was listed in serious condition after the collapse.

According to a media source, the concrete was being poured into a metal frame when the structure gave way.

Most of the reported injuries were "cuts, scrapes, lacerations, broken bones, wrists, things of that nature," one hospital spokesperson said.

However, the worker in serious condition was at another hospital. His injuries weren't described in the media report we read.

The 13 injured construction workers were taken to three different nearby medical facilities.

The workers were helping erect the Horseshoe Casino in downtown Cincinnati. When completed, the casino will have 100,000 square feet of gaming area. The project is scheduled to be completed late this year, but work on the site came to a halt after the accident.

The Labor Department's Occupational Safety and Health Administration is conducting an investigation to see what went wrong.

One woman quoted by a media source is the sister of an injured worker. She said her brother told her from his hospital bed that he didn't know what had happened.

"They were working and it just started falling," she said. "He said it was very scary and (he) just ran. That's all he could do."

Source: WCPO: "3 of 13 workers hurt in casino construction accident still hospitalized," Tom McKee, Jan. 27, 2012