Investigators in Mount Forest are making progress after a fire on Sunday injured a firefighter and left at least fifteen people homeless.

Wellington North Fire Chief Dave Guilbault tells CTV News nearly half of the smoke alarms inside the building were not functioning and says the outcome could have been much worse if the fire broke out in the middle of the night.

“After the fire was extinguished, we went apartment by apartment and we found two units where smoke alarms were tampered with and two were not working and I find that very disturbing,” says Chief Guilbault.

The firefighter who was injured was sent to hospital after a portion of the ceiling collapsed on top of him. He has since been released and will likely be recovering for weeks.

The Fire Chief says two tenants have admitted to tampering with the fire alarms in their own units. Guilbault says he will be speaking to the crown prosecutor this week about laying charges under The Fire Protection and Prevention Act which carries a maximum fine of $50,000.

“I believe there are going to be several charges laid most likely to the owner and to the tenants. Your first line of defense is a smoke alarm and by disconnecting one you are putting yourself and everybody else in this apartment at risk,” says Guilbault.

The Ontario Fire Marshal’s office is still investigating; they suspect the cause may be electrical.

Damage is pegged at $500,000.

Guilbault says it will likely be months before some of the tenants are allowed to return home.