A Grant County teenager is dead after police say he fell into an irrigation canal early Sunday. The Grant County Sheriff's Office says 18-year-old Johnny Sanchez-Mendoza of Mattawa was driving his vehicle near the 7900 block of Wahluke Slope Road Southwest when it became stuck in a concrete canal chute. Get our free mobile appDeputies say as Mendoza and a passenger in the vehicle were attempting to push the vehicle free, Mendoza slipped and fell into the canal where he was swept away by swift-moving water. Mendoza was found about a half-a-mile away where he was pronounced deceased by first responders. The Grant County Coroner's Office will conduct an autopsy this week to determine Mendoza's exact cause of death.