MT – Billingsly Gazatte – City Hall was evacuated Tuesday after utility workers found “extremely high levels” of carbon monoxide in the building, a Miles City Fire Department captain said.

The evacuation occurred soon after new members of the City Council took their oaths of office at 9 a.m. The building reopened in the afternoon.

“What was amazing was when we went in, there was a faint smell, but when we came out, it would just about knock you down,” said Mayor Butch Grenz.

Fire Capt. Kevin Quinlan said he and two other firefighters were called to ventilate the building, because workers for Montana-Dakota Utilities had detected high levels of carbon monoxide.

According to Quinlan’s report, employees of the utility and a plumbing firm checked the furnace and water heater, and determined a fresh-air vent was almost covered. Carbon monoxide from the boiler exhaust was drawn back into the building.

Grenz said more than 30 people were in the building when he ordered everyone to leave, before firefighters arrived.