Investigators are working to determine the cause of a blaze at a home that was under construction in the city’s southwest and say four people were able to self-evacuate after the fire spread to a neighbouring home.

Crews were called to a home in the 200 block of Aspen Ridge Heights at about 6:30 p.m. Sunday and called in a second alarm due to the large amount of smoke.

The home under construction was fully involved in flame when crews arrived and the fire had already spread to the roof of a neighbouring home.

“The house that was under construction has extensive damage to it and there is significant damage to the neighbouring home as well, which is occupied,” said Carol Henke, CFD Public Information Officer.

Firefighters were able to enter the occupied home and put out a fire in the attic once the flames were extinguished on the outside.

“The house under construction was fully involved, which is a very dangerous situation so the initial tactic is to go defensive, which means you put water on from the outside. Once you’ve doused a lot of the flames and you’ve got the fire under control, you can actually go inside and do a search, if it’s safe to do so. Fire moves very quickly and can damage the structural integrity of the homes such that it’s not safe for firefighters to even go inside,” said Henke.

Four people in the occupied home were able to get out safely and no one was injured in the incident.

“Currently, we still have a fire investigator on scene sifting through the damaged homes to look for an exact origin and cause but we do know that it started with the home under construction,” said Henke.

Fire crews remained at the scene over night to monitor for hot spots and the cause of the fire is under investigation.