The third floor of a suburban building under construction collapsed as workers were pouring concrete Friday, injuring six people and temporarily trapping one.

Maple Grove Police Chief Mona Dohman said the trapped man had an injured arm and was able to talk with rescuers, who eventually freed him.

Neither he nor the other five workers taken to hospitals were believed to have any injuries considered life-threatening, officials said.

Dohman said the accident happened as the workers were pouring concrete on the third floor, which collapsed down into the second. The construction site is for a new headquarters for Great River Energy, a wholesale power supplier.