MONTREAL -- The Samuel de Champlain Bridge has reopened to traffic after a truck caught fire Monday morning.

According to the Sûreté du Québec (SQ), the incident happened at 6:15 a.m. The truck was on the bridge when its tires ignited.

The northbound span was completely closed to traffic to allow firefighters to extinguish the flames, but was reopened at 8 a.m.

It is not yet known why the truck’s tires caught fire. The southbound lanes were not affected.