The cause of a fire that erupted Saturday evening at 141 E. Gorham St. is still under investigation.

According to a Madison Fire Department incident report:

Firefighters from Engine 1 arrived at the scene shortly after 8:15 p.m. when a resident called 911 after a smoke alarm was triggered in a first floor unit. There was no response from within the reported apartment unit, prompting firefighters to break down the door.

After being met with a large billow of smoke, two more engine companies, two ladder companies, a medic unit and command car responded to the call. Seconds after Engine 1 discovered the smoke, the fire spread to the second and third floors.

By 9 p.m., the fire had evolved into a two alarm fire, sending more companies to the scene while crews battled the spreading fire.

Three hours and 47 firefighters later, the blaze was extinguished.

All residents and emergency responders escaped unscathed, with Metro providing a warming bus for displaced residents.

The cause of the fire is unknown and damages are estimated at $250,000.