DES MOINES, Iowa – A fire at the Capital Square building in downtown Des Moines forced an evacuation Thursday morning and left behind damage from flames, smoke, and water.

A call from the fire alarm system at the 400 Locust Ave. building came in at 7:37 a.m., according to Lt. Rick Thomas. Fire crews arrived just a few minutes later and discovered a fire on the third floor in an open room.

The fire had spread to a second room but firefighters were able to extinguish the flames by 8:02 a.m.

Crews had to break some windows on the third floor to allow smoke to vent out of the building.

Lt. Thomas say they aren’t sure whether there was anyone on the third floor at the time the fire started, but there were people working in the offices below on the second floor.

Greg Edwards, President and CEO of the Greater Des Moines Convention & Visitors Bureau, which has offices on the second floor of the building says employees told him they heard water trickling down into their offices before the evacuation, indicating the sprinkler system was on and running before any alarm was issued.

Lt. Thomas did not know when people would be allowed back into the building.

The cause of the fire is still being investigated.