Fruit Street School pupils lost their lunch Friday morning when they had to be evacuated briefly when a school alarm was set off. The 300 pupils were served breakfast, including cold cereal, fruit and crackers, when their hot pizza lunch was ruined by a sprinkler going off in the school’s kitchen. The Fire Department responded to an alarm which was automatically set off by the sprinkler, according to Principal Joe Dahl. Assistant Fire Chief Scott Bostock said that the problem was a puff of smoke and excessive heat from an oven that triggered the sprinkler in the kitchen. Pupils were outside for about 20 minutes before they were allowed back into the gymnasium. The only damage was the loss of a few ceiling tiles, according to Bostock. The Fire Department, along with the maintenance staff, cleaned up the water quickly to prevent further damage, the principal and assistant chief said.