Madison apartment evacuated due to lethal levels of carbon monoxide


MADISON, Wis. — An apartment building near the UW campus was evacuated Monday after dangerously high levels of carbon monoxide were detected.

Madison Gas and Electric and Madison Fire Department crews were called to the 128-unit building in the 1000 block of University Avenue just after 5:30 p.m. Carbon monoxide readings of about 500 ppm were found in an upper floor, and readings over 250 ppm were found on other levels.

According to the Consumer Product Safety Commission, prolonged exposure to CO levels above 150 ppm can be fatal.

Crews used multiple fans to ventilate the building and went door to door evacuating residents. Firefighters found that multiple units had high levels of CO, and some residents had removed the batteries to their CO detectors.

Residents had to stay out of the building for about two hours while it was ventilated. Two people showed mild symptoms of CO poisoning but neither was taken to the hospital.

Madison Fire Department officials said the CO build-up was caused by a service van that had been left on for several hours near an exterior stairwell door.