Madison firefighters found about 90 ppm of CO in locked basement mechanical room | The Locally Times
Published · The Locally Times
Madison firefighters measured approximately 90 ppm of carbon monoxide in a locked basement mechanical room on Royster Oaks Drive on September 29.
Madison Fire Department L8 responded to the 900 block of Royster Oaks Drive at 6:07 a.m. on September 29, 2026, for a reported carbon monoxide alarm. The resident told firefighters the combined smoke and carbon monoxide detector had been sounding intermittently for more than 24 hours, beginning sometime Sunday. She reported a mild headache, was the sole occupant, and called 911 after realizing the device was a smoke and carbon monoxide detector. Firefighters measured carbon monoxide levels of up to 70 ppm inside the apartment, where a gas-fired furnace sat in a locked bedroom closet with the thermostat off. In the basement, water heaters sat inside a locked mechanical room where readings reached approximately 90 ppm. L8 ventilated the apartment with a positive-pressure fan and ventilated the mechanical areas naturally and with a small blower unit. ## What the record shows MGE arrived, investigated further, and identified abnormally high carbon monoxide readings from the exhaust system. Building management and maintenance personnel were contacted, and L8 cleared the scene after MGE assumed responsibility for the investigation. The fire department's report reminds residents that carbon monoxide cannot be seen, smelled, or tasted, and that a working CO alarm provides warning when dangerous levels are present.