A head-on collision in Brampton, Ont., has sent a number of people to hospital.

A pickup truck and a Ford Focus collided in the northbound lanes of Dixie Road south of the Sandalwood Parkway at around 1:45 p.m. on Monday afternoon.

Witnesses report the black truck was weaving in and out of traffic at high speeds when it crossed the median into the northbound lanes, became airborne and landed on the car.

The northbound car then spun out of control and struck another vehicle.

"My wife was with me and she said, 'Look at the way people drive on the roads today,' and no sooner, I saw this truck go right up into the air and smack the car," witness Peter Canali told CTV News from the scene on Monday.

An air ambulance transported a 32-year-old-woman, the driver of the car, to Sunnybrook Health Services Centre with life-threatening injuries.

One of two children in the car was taken to Peel Memorial Hospital with non-life threatening injuries. The second child was uninjured in the crash.

The two people in the pick up truck were also taken to hospital.

No one was injured in the third vehicle.

The names of the victims have not been released and police are investigating the cause of the crash.

Police say Dixie Road from Sandalwood Parkway to Spring Town Trail is expected to stay closed for a number of hours.

With a report from CTV's Naomi Parness