UPDATED: 3:44 p.m.

The fire alarms in Memorial Hall sounded at around 11:40 a.m. today, leading to an evacuation of the building.

Interrupting a lecture of Ethical Reasoning 22: "Justice," the sounding of the alarms was not a prank, according to Tina Bowen, a production manager at the Office of the Arts who works at Memorial Hall.

“I was so thrilled to see the use of the emergency exits [in Sanders Theatre]," she said. "I came into the theater to encourage people to use them, and everyone already was.” Students had also evacuated from Annenberg and the Loker Commons.

Raymond Traietti, the assistant director and building manager for Memorial Hall, told us that the alarm had been triggered in the Annenberg kitchen, but the Cambridge Fire Department found no actual fires. (We thought that was smoke in the photo, too, but it must have been something else. Steam from the sprinklers, perhaps?)

Traietti told us that fire alarms go off in Memorial Hall approximately four or five times per year. "There are such an intense array of suppression systems, and it is so complicated, that you are bound to get mishaps," he said.

Fires are of special concern to Memorial Hall staff because the building suffered significant structural damage from a 1957 fire.

The all-clear was given a few minutes after noon, when everyone was allowed to reenter the building.

Photos by Miranda K. Lippold-Johnson/The Harvard Crimson.