Toronto police are appealing for witnesses in a late-night crash that left an elderly couple with serious injuries.

Investigators say the married couple was driving in a car on Kingston Road near Brimley Road when their vehicle slammed into a parked tow truck at about 10 p.m. on Friday.

The 73-year-old woman suffered a fractured skull and police describe her injuries as life-threatening.

Her 72-year-old husband suffered severe lacerations to his head and face and a broken right arm, police said.

Investigators were trying to piece together what led to the crash.