Three people are dead and a fourth was rushed to hospital after a collision on Highway 404, near Stouffville, Ont., on Tuesday afternoon.

The two-vehicle crash occurred at approximately 4:50 p.m. near Stouffville Road.

OPP Sgt. Kerry Schmidt said the incident occurred when a southbound vehicle came off the road, travelled across a grass median, and collided head-on with a car in the northbound lanes.

“It’s a massive collision scene…The damage to the vehicles is incredible,” he said.

Schmidt said it is unclear why the southbound car left the roadway.

“Typically, we don’t see these kinds of collision on divided highways,” he said.

The three deceased were all travelling in the same car, Schmidt said. The person taken to hospital was in the other vehicle.

Police have not released any details about the victims’ identities.

Northbound lanes of the highway between Elgin Mills and Stouffville Roads were closed while police investigated the accident, but have since reopened.

The left lane of the southbound side of the highway was also closed, but was reopened on Tuesday afternoon. 

Police are asking drivers who may have witnessed the accident to come forward.