Madison, WI – Nearly 100 people were evacuated from a Madison shelter, just hours after an overnight storm dropped several inches of snow on the city.

The evacuation effort began around 4:30 a.m., shortly after a staff member detected a gas odor so potent that one staff member at the shelter, at N. 1st St. and E. Johnson St., reported feeling lightheaded.

Three Madison Metro buses were dispatched to pick up the residents to take them to other shelters. In all, there were 94 people staying there at the time, according to the shelter manager Preston Patterson.

Many of the people at the shelter were taken to The Beacon, a day-time resource center for the homeless, after it opened early Wednesday to welcome them. The rest chose to leave the shelter on their own.

According to Madison Police, a faulty heater caused carbon monoxide levels at the facility to rise, which prompted the evacuation.

People will be allowed back once CO levels have decreased and it is safe to return.