Quebec ? An overpass near Montreal collapsed Saturday, crushing two cars whose occupants were feared dead, authorities said. At least five people were injured.

Drivers on Highway 19 slammed on their brakes and watched in horror as the overpass slowly collapsed, sending cars plunging and crushing at least two vehicles. Quebec provincial police did not confirm any deaths, but spokeswoman Chantal Mackels said police thought it was unlikely that anyone in the crushed cars survived.

Ambulances transported five people. Three were in critical condition, including two suffering from head injuries.

Emergency workers had not yet reached people trapped under the wreckage, said Andre Champagne of ambulance service Urgence-Sante. The workers were trying to secure the site before attending to those trapped, he said.