A carelessly tossed cigarette butt was the probable cause of a $1500 blaze on the top floor of Thayer Hall last Friday, fire department officials announced.

The alarm, rung in from box 481 at University Hall at 9:29 o'clock, brought three engine companies, two ladder companies, one rescue company, and countless delighted students to the scene. Brought to the public eye by the fire was the fact that the University Hall warning signal is the only fire alarm box in the Yard. A few minutes' delay occurred when the Navy sentry who first reached the call box failed to pull the alarm lever.