This is a tragic loss to the families of those onboard and to the medical air and first responder community,” Navajo police said in a social media post. “We extend our deepest condolences to their family and loved ones during this time.

Cellphone footage shows black smoke rising from a medical transport plane that crashed and caught fire on Tuesday in the Navajo Nation in northern Arizona, resulting in the deaths of four people, according to a statement released by the tribe.