An automatic sprinkler system kept a fire on the balcony of a West Dundee apartment from spreading into the building early Friday morning, officials said.

A water gong alarm at 3:08 a.m. woke residents of a second-floor unit on the 3100 block of Canterfield Parkway East, and they soon realized the furniture on their balcony was on fire, according to a news release from the village.

All residents of the building had evacuated by the time firefighters arrived. Firefighters extinguished the blaze, which authorities believe was caused by careless use of smoking materials, within five minutes, the news release said.