Carbon Monoxide Disaster Averted

A full structure response was dispatched to the 2500 block of Calypso Road when a caller complained of carbon monoxide detectors sounding in the building and smoke visible from the basement. 
Upon investigation by first arriving crew, Engine 10, there was a gas operated pressure washer in the basement that had reportedly been running for more than 6 hours causing exhaust smoke accumulation and a buildup of carbon monoxide.   The Hazmat HIT Leader was consulted for atmospheric mitigation. The 2 story/8 unit apartment building was evacuated for safety purposes and ventilated appropriately when carbon monoxide was detected at a high level throughout the structure.  Meanwhile Madison Metro responded with a bus for the building occupants to temporarily reside. 
A 10 month old was evaluated and released on scene.  Once the carbon monoxide readings were well below harmful levels occupants were allowed back into their homes.