A broken exhaust fan is blamed for carbon monoxide building up inside the underground garage of a Madison apartment building.
According to the Madison Fire Department, someone pulled into the garage, in the 90 block of Kessel Court, on Monday night and called 911 after hearing an alarm and noticing an odor. When firefighters responded to the building around 9:20 p.m., they reported seeing a haze they suspected was car exhaust.
They tested the air and found carbon monoxide levels reached 115 parts per million, more than double what the federal Occupational Safety and Health Administration considers a permissible exposure limit. In the hallways of the apartment building, they detected levels of 35 ppm.
After confirming the elevated CO levels, the firefighters spotted the exhaust fan that was not working. They brought in their own fan to start clearing the air in the garage. While they were doing that, another fire crew started ventilating the hallways and stairwells.