Aberdeen, SD – High levels of carbon monoxide led to the evacuation of the local United Way office Monday morning, the executive director of the agency said.

Aaron Schultz also said three apartments in the building, at 12 Fourth Ave. S.E. in downtown Aberdeen, were also evacuated. He said that when he arrived at the office on Monday morning, the carbon monoxide sensors were going off, so he called the fire department to have the levels checked.

The excess carbon monoxide was likely coming from the heater, which was turned on last week, he said.

Will Christman said he and five relatives live in the three upstairs apartments. He said he was sleeping and most of the others were home at the time of the evacuation, which was around 10:15 a.m.

Christman said he was also told the carbon monoxide was likely coming from the heater.

Firefighters responded using fans to air out the building.

“They acted pretty fast, so that’s a good thing,” Christman said of the firefighters.

JR Huebner, battalion chief with Aberdeen Fire and Rescue, said people were allowed back in the building about 11 a.m. The heating system was shut down while the building was ventilated and a repair technician was called to make the necessary fixes, he said.

This is the time of year for people and businesses that have gas-operated heaters to make sure they have carbon-monoxide sensors in place and do necessary maintenance on the systems, Huebner said.