Two people were killed and two were seriously injured — including a child — in an "absolutely devastating" five-vehicle crash in Georgina, Ont., Ontario Provincial Police say.

Two people were pronounced dead at the site of the noon-hour crash on Highway 48 near Old Homestead Road, OPP Sgt. Kerry Schmidt said. 

Five vehicles were involved in the fatal crash, including three gravel-hauling trucks, a commercial vehicle and a passenger vehicle, he said.

Georgina fatal collision

A collision reconstruction unit is at the site of the crash. (Martin Trainor/CBC)

Schmidt said an occupant of the passenger vehicle and an occupant of the commercial vehicle were killed.

An adult and child were airlifted via Ornge air ambulance to trauma centres with critical injuries. The child, said to be 10 years old, is now in stable condition at Sickkids.

It took nearly 90 minutes for firefighters to extricate the adult victim out of the passenger vehicle, York Region Paramedic Services said.

Another adult with minor injuries was taken to a local hospital by paramedics.

Georgina fatal crash

Two people are dead and a child is among two critically injured in a multi-vehicle crash in Georgina, Ont. (Martin Trainor/CBC)

Vehicles 'crushed beyond recognition' 

An investigation into the crash is underway.

Schmidt said all five vehicles were travelling northbound on Highway 48, adding that there is a slight crest in the roadway and construction up ahead.

"Some of the lead vehicles were stopped, waiting for their turn to travel northbound. At the time of the collision, at least one of the rear vehicles approached at highway speed or at a much greater speed causing a sequence of events that resulted in the collision."

Georgina fatal crash

Two people, including a child, were airlifted to hospital with critical injuries. (Martin Trainor/CBC)

"The collision damage of these involved vehicles is absolutely devastating," Schmidt told CBC Toronto.

He said the commercial vehicle and passenger vehicle were "absolutely crushed beyond recognition." 

Highway 48 is closed between Old Homestead Road and Latimer Road, Schmidt said.

"It will be some time before we get the highway cleaned up," he said, estimating eight to 10 hours before the roadway could reopen.

Two firefighters were taken to hospital for assessment after working under hot and humid conditions.