MINNEAPOLIS (WCCO) – Authorities say a building near the University of Minnesota campus had to be evacuated Tuesday night due to a carbon monoxide leak.

The Minneapolis Fire Department responded to the incident shortly after 8 p.m. on the 1000 block of University Avenue SE. When crews arrived, they detected carbon monoxide levels of 200 parts per million and evacuated the building.

Fire officials determined the source of the leak to be a generator being used for a power washer in the basement of the building. Levels got up to 500 parts per million before the generator was shut down.

Authorities say the building was cleared after primary and secondary searches, and nobody was injured. They’re ventilating the building until carbon monoxide levels hit zero.