Updated

Police in Arizona say three people are dead after a crash involving an ambulance and two other vehicles.

Police say witnesses told investigators that a speeding car ran a red light and struck an ambulance in a Tucson intersection Sunday. The force of the collision knocked the ambulance onto its side, and both vehicles struck a pickup truck stopped at the red light.

Police say a 71-year-old man in the ambulance, a friend of the person being transported, died at the scene. Two medics and the patient suffered minor injuries.

Police say the 20-year-old driver of the car and a 25-year-old passenger died. Two other passengers were taken to a hospital, one with life-threatening injuries and one with serious injuries.

The 18-year-old driver of the pickup suffered minor injuries.

Police are investigating whether speed and alcohol played a role in the crash.