Overcooked food activated the fire alarms at Warren Towers at about 6:10 p.m. Monday, according to a sign posted after the alarms were turned off.

Residents of Shields, or ‘C,’ Tower, and students who were on the fourth floor which includes the building’s dining hall were ordered to evacuate after the main alarm went off. Students from the other two towers said they remained in their rooms and were not asked to leave.

Eyewitnesses, including College of Arts and Sciences freshmen Kate Joyce and John Mock, said they saw smoke coming from C Tower Area Director T. David Reese’s fifth-floor room, and they reported it to their resident assistant.

‘It was [Reese’s] apartment,’ Joyce said. ‘It was smoking for, like, an hour and a half.’

Mock also said he saw smoke for more than an hour, and the main alarm only went off after firefighters and Boston University Police officers arrived. Mock said he saw about eight firefighters outside the room.

Firefighters broke down the door to Reese’s room, and pieces of the broken door handle remained on the floor after students returned.

Reese did not return phone calls Monday night, and the Boston Fire Department could not be reached for comment.

Staff writer Brittany Lawonn contributed to this report.