Dallas police say a pickup truck driver fled on foot after hitting and killing three men trying to change a flat tire along a freeway.

Police say the men who were killed were standing outside a disabled SUV when the pickup struck them around 3:30 a.m. Sunday. Police say the pickup also hit the sport utility vehicle.

Two people inside the SUV were hospitalized, one with severe injuries.

Police say the pickup driver left behind a 13-year-old boy who was in the truck with him. The 13-year-old was taken to a hospital.

Police are searching for the pickup driver, who they say will be charged with manslaughter and failure to stop and render aid.