Four people were killed in three separate crashes over the weekend and two drivers could be facing charges.

It all began on Saturday morning when a 79-year-old woman was struck by a car as she was crossing Bow Trail near 37 St. S.W. just after 10:00 a.m.

The woman suffered severe head injuries and was transported to hospital where she later died.

Witnesses at the scene say the woman was in the crosswalk at the time and was crossing under a 'walk' signal.

Police say that sun glare may have had something to do with the crash.

Charges are pending against the 25-year-old driver.

Then, in the early morning hours on Sunday, two people were killed when a Toyota Yaris crashed into a Mercedes at the intersection of Country Hills Blvd. and Shaganappi Trail N.W.

According to witnesses, the northbound Yaris was speeding and drove through a red light when it T-boned the westbound Mercedes.

The 20-year-old driver of the Mercedes, Arsh Brar, was killed as a result of the crash.

The passenger in the Yaris, Danni-Victoria Russell, 21, was also killed in the crash.

The driver suffered minor injuries and was transported to Foothills Hospital.

Police are continuing to investigate and believe that speed and alcohol contributed to the crash.

Charges are pending.

Also on Sunday, a motorcyclist was killed when he crashed into a truck in Forest Lawn in the afternoon.

The crash happened in the area of 19 Ave. and 36 St. S.E.

Police believe that the 30-year-old motorcyclist was speeding at the time of the crash.

The driver of the truck was not hurt.