LEEDS, Ala. - Several workers were injured and others were trapped when a roof collapsed Thursday at a clothes hanger factory, fire and police officials said.

Ambulances took injured workers to hospitals after the collapse at M&B Hangers around 9:25 a.m. in Leeds, near Birmingham. None of the injuries appear life threatening, authorities said.

It wasn't immediately clear why the roof collapsed, or how many people were inside. WBMA-TV reported that construction crews were working on beams inside the building. An infared camera was being used to make sure no one was still trapped, and rescuers had to help some people get free from the debris.

Company officials did not immediately return a call about the accident.

M&B is one of the nation's largest makers of clothes hangers, and it's one of only a handful of hanger companies remaining in the United States.