Kansas City, MO – Three people who were sickened by carbon monoxide received medical treatment Monday after evacuating a Kansas City marketing agency building.

Firefighters responding to a 12:08 p.m. call regarding shortness of breath found high levels of carbon monoxide at Sullivan Higdon & Sink, 2000 Central St. in the Crossroads Art District.

“We had two patients when we arrived; one critical, the other non-critical,” Kansas City Fire Department Battalion Chief James Garrett said. A third person left to obtain medical treatment, Garrett said.

No agency employees were sickened, said Melissa Racer, the agency’s public relations director. A construction crew had been working in the building, she said.

Firefighters determined that power equipment being used in the building’s basement created the carbon monoxide, Garrett said. Firefighters shut off the equipment and ordered an evacuation.

Firefighters measured the concentration of carbon monoxide at about 1,300 parts per million, about 26 times higher than the danger threshold.