4 dead, 12 injured in multi-vehicle accident on highway north of Montreal

Four people are dead and 12others injured after a small cargot stuck underneath a semi-trailer, causing a major accident Monday afternoononHighway 440 in Laval, Que., about 27 kilometres north of Montreal.

After the car and semi-trailer struck each other they collided with another truck, said Christian Grand'Maison of the Laval fire department.That started a chain reaction that eventuallyinvolved another six vehicles. One of these also got stuck underneath a semi-trailer, Grand'Maisonsaid.

Provincial police had initially said only three vehicles were involved with the crash.

• Update:Public's help sought to determine cause of Laval highway crash that left 4 dead, 15 injured

The collision ignited a large fire, andsmoke could be seen from several kilometres away.

Three people were pronounced dead at the scene. A fourth body was found in the wreckage Monday evening.

Twelve others were taken to hospital, including some first responders. Three of those are in critical condition, police said.

First responders discovered about 10 small canistersof propane inside one of the trucks, along with household items.

Grand'Maisonsaid the propane may have triggered a minor explosion. The other truck was transporting vegetables.

The fire broke out around 3:30 p.m. ET Monday, near IndustrielBoulevard. Firefighters had the blaze under control by 5 p.m.

Highway 440is an east-west route that runs between Highways 13 and 25. The highway reopened to traffic at around 5 a.m. Tuesday.