A two-car crash on Highway 427 has killed one woman and closed a large section of the west Toronto highway on Saturday morning.

The cars collided in the northbound lanes near the Eglinton Avenue exit at about 8:30 a.m.

Ontario Provincial Police Sgt. Sandy Cain told CTV.ca that police are trying to determine what caused the woman who died to lose control of her vehicle.

Northbound traffic from Highway 427 was diverted to Highway 401 westbound. The northbound lanes were closed between Eglinton and Highway 401.

Investigators are at the scene and seeking help from anyone who witnessed the crash.

In Peel region, police were investigating another serious crash that happened overnight.

Police say high speeds are likely to blame for the crash that put a 34-year-old man in serious condition in hospital.

The man's car was travelling westbound on Eastgate Parkway when it mounted the median and crashed into a cement light standard, causing it to crash down on the car.

The impact cut the vehicle in half. The man has been taken to a local trauma centre.

Police have interviewed several witnesses and are trying to determine if alcohol or drugs were also a factor in the crash.