A computer on a couch is to blame for a fire that caused a residence for university students in Waterloo to be evacuated, fire officials say.

Fire crews were called to the Bricker Avenue residence around 8 p.m. Monday.

“When crews arrived on scene, they encountered heavy smoke in the hallway,” said deputy fire chief Richard Hepditch.

They also encountered summer students who had noticed the fire and gathered outside the building.

“I glanced over my shoulder and saw orange windows,” said Andrew Jenkins, who lives in a neighbouring building.

The fire was contained to the first-floor unit where it started, but smoke found its way into several other units.

Fire officials say it’s not the first time they’ve seen a fire start when a laptop was left running on a couch, sparking flames on a flammable couch cover or blanket.

Damage is estimated at $75,000.