Students evacuated the Cathedral of Learning last night after a cigarette butt smoldering in… Students evacuated the Cathedral of Learning last night after a cigarette butt smoldering in a trash can caused a lot of smoke.

Captain Jim Talak, acting battalion fire chief for the city, said someone pulled the fire alarm after seeing the smoke, which came from a trash can on the ground floor.

Junior Mickey Szlachta said he was in class on the second floor of the Cathedral when the fire alarm went off and a loudspeaker announcement instructed people to evacuate the building. He said the alarm sounded between 6:05 and 6:10 p.m.

By about 15 minutes after the evacuation, students had heard it was a trash can fire. Some students said they smelled burning plastic while exiting the building, whereas others said the smoke smelled more like burning leaves or a campfire. Some students also saw smoke in the stairwells as they left.

The evacuation displaced hundreds of students in the Cathedral. Some professors conducted class outside, forming circles scattered across the lawn.

The Cathedral reopened within an hour.