The Appleton Fire Department says a kitchen fire in an apartment building was stopped by the apartment's fire sprinkler system. The fire department was alerted to the fire on the 400-block of N. Richmond St. at 6 o'clock Monday morning by a water flow alarm from the sprinkler system. The fire started in a combination vent hood and microwave oven in the kitchen of a vacant apartment. The apartment was being cleaned. The oven was put on a self-cleaning cycle and a fan in the vent hood was left running. The fire department says the sprinkler system contained the fire until firefighters arrived and kept conditions survivable for other tenants to escape. "The sprinkler system in this building operated as designed, keeping this incident from being a major disaster," a statement from the fire department reads.