Three fire stations responded to a call on Dutrisac Street because of a pot on a stove. According to Montreal Fire Chief Serge Tremblay, the man would have stepped off the truck and was somehow struck by it.
The firefighter was brought to the hospital in critical condition and succumbed to his wounds later in the day.
The reason for the incident remains unknown but is being investigated by Quebec Workplace Health and Safety Board and Montreal Police.
Two other firefighters were treated for shock.
At a news conference on Friday night, Tremblay said "Our firefighters, they're very competent. They have a lot of training."
He insisted that firefighters are trained to follow guidelines.
Montreal Mayor Gerald Tremblay issued a statement wishing his condolences to the man's family.
"In the name of all the elected representatives, my name and my wife Suzanne, I would like to offer my deepest condolences to his family, his friends and his colleagues."
This is the first time a firefighter has died on the job in Montreal since 2006.Suggest a correction