Investigators are still trying to determine the cause of a fire that broke out early Monday morning in the Minneapolis Police Department's property room, but they don't suspect foul play.

The fire in the subbasement of City Hall started around 1 a.m. but was quickly put out by automatic sprinklers in the room. Smoke drifted to the adjacent 911 call center, but no 911 equipment was damaged and dispatchers carried on with their work.

By Monday afternoon, police officials were still sorting through the property room to determine the extent of the damage from fire and water.

Police spokesman John Elder said the department acted quickly after the fire to set up security in the area to "maintain the integrity of the evidence" stored there.

Elder said he wasn't sure of any specific prohibitions on storing flammable materials in the basement. The property room is not staffed around the clock, but workers are always in the nearby dispatch center.

City officials said they were thankful the dispatchers at 911 were able to continue working during and after the fire. Calls were covered by a 911 center in the Police Department's Third Precinct office on Monday.

"Minneapolis 911 staff went above and beyond to provide critical emergency services to our residents, even as smoke filled parts of the 911 center," said Mayor Betsy Hodges. "They acted with cool heads and an extraordinary dedication to our residents."

Staff writers Tim Harlow and Paul Walsh contributed to this report.

Erin Golden • 612-673-4790