Pressure washer blamed for carbon monoxide leak at Madison apartment building

MADISON, Wis. (WMTV) - The City of Madison Fire Department responded to an apartment building for a carbon monoxide leak on the west side of Madison Saturday afternoon after an alarm on the third floor was activated.

Firefighters responded to the 700 block of Knickerbocker St just after 1:30 p.m., where residents had reported feeling ill. While in the elevator of the building near the third floor where the alarm was activated, MFD’s air monitors alerted them to carbon monoxide levels of about 80 ppm.

On the third floor, CO level readings were between 60 and 70 ppm.

MFD was able to retrieve a fan, and when beginning to ventilate the hallways, ran into a cleaning crew at the apartment building. The crew stated they used a a gas-powered pressure washer in the basement to clean the parking lot.

The crew had already completed their work, but were advised by Madison Firefighters to not use the gas-powered equipment indoors again.

Firefighters returned to the building and ventilated each floor. They also propped open the garage doors to clear the air. They were able to clear the scene once CO levels dropped below 5 ppm.