NEW YORK (CBSNewYork) — 10 firefighters and one civilian were hurt when a four-alarm fire ripped through a building in Midtown Manhattan Tuesday afternoon.

The FDNY says flames broke out at 21 West 39th St. around 4:30 p.m. and quickly spread through the ducts.

Ten firefighters and one civilian were hurt as crews worked to extinguish the blaze, according to the FDNY. Officials say two of the firefighters were rushed to the hospital in serious but stable condition.

The cause of the fire remains under investigation.