An automatic alarm system is being credited by firefighters for saving lives during a fire in Naperville early Wednesday morning.

Firefighters from the Naperville Fire Department were called to the 800 block of Beaumont Drive by an automatic fire alarm that triggered after a fire started inside a residential building at 12:44 a.m., authorities said in a news release.

The first firefighters arriving on scene reported heavy smoke showing from the first floor of the complex, authorities said.

Firefighters searched and evacuated the building.

The fire was under control and extinguished within 15 minutes, authorities said. No residents or firefighters were injured in the blaze.

A brief investigation determined the fire came from a first-floor laundry room clothes dryer. The unit where the fire originated was deemed uninhabitable, authorities said, and the Naperville Fire Department assisted in relocating the residents.

All other occupants of the complex were allowed to return to their homes.

Authorities credited the presence and proper operation of the automatic fire alarm system for the safe evacuation of the building and early notification to the fire department, authorities said.