Two single-engine planes collided in midair and crashed into barren desert terrain just north of Phoenix Friday morning, killing four unidentified people traveling in the small aircraft, according to fire officials.
Fire officials who responded to the scene of the crash discovered two bodies onboard each of the planes -- one of which had caught fire and was consumed by flames while the other was only partially damaged, according to Phoenix Fire Department spokesman Capt. Larry Nunez.
All four people were pronounced dead at the scene by responding paramedics, Nunez said.
A pilot reportedly spotted the two small planes plow into each other just after 10 a.m. local time Friday morning, roughly 15 miles northwest of Deer Valley Airport in Phoenix, according to preliminary information from Federal Aviation Administration spokesman Ian Gregor.
Authorities do not yet know what caused the fatal collision and have not determined the official cause of death for the four bodies found at the scene, Nunez said.
The FAA and the National Transportation Safety Board will investigate the incident. Three FAA inspectors are already at the scene conducting a preliminary review, according to Gregor, but he added it could take months before officials determine the cause of the collision.