Classes at Messmer Preparatory Catholic School were canceled Friday after an early-morning fire on the south end of the building. School president Jim Piatt said a staff member arriving for work at about 6:30 a.m. heard the fire alarm and called authorities. Firefighters quickly arrived at the school, located on the 3000 block of North Fratney Street in Milwaukee's Riverwest neighborhood. Piatt said the fire appeared to be electrical in nature and was confined to a small attic space. No students were in the building, but those who arrived as firefighters were on the scene were taken to Messmer High School for pickup by parents. Classes are also canceled on Monday for the Labor Day holiday, giving students at Messmer Prep a four-day weekend.