Police are trying to figure out exactly what caused a truck to careen into a garden centre set up in the parking lot of a big box store in Scarborough , injuring an elderly pedestrian.

The accident happened just after 12:30pm Friday at the Wal-Mart at Kennedy and Sheppard. The driver of a pickup lost control, drove over a sidewalk and crashed into the outdoor shopping display and hit a 75-year-old woman.

The incident was made worse because the driver's foot didn't come off the gas after he hit the store, and the rear tires burned rubber until emergency crews were able to get him out.

The victim was taken to hospital with injuries police described as non life-threatening. The driver of the truck was also transported with minor injuries.

Officials suspect a medical problem may have been behind the accident.