No other victims or survivors have yet been found following the accident at Superstition Mountain.
Pinal County Sheriff Paul Babeu said it was believed the plane crashed shortly after taking off from nearby Falcon Field, where the pilot had picked up his three children. plane crash webcam,
Authorities started receiving reports of an explosion about 6:30pm local time.
The pilot was also believed to have been accompanied by a mechanic and another adult, Mr Babeu said.
"From what we heard, this plane left from Safford to Falcon Field in Mesa to pick up children for Thanksgiving to go back to Safford. So it's heartbreaking if that's the case," Babeu said.
It was when they were returning to Safford that the twin-engine aircraft went down, exploding in a huge fireball about 64km east of Phoenix.
Footage caught on a webcam showed a huge flash, apparently as the plane exploded.
Emergency crews were struggling through rugged terrain to reach the crash site, while helicopters were also flying overhead with infrared lights searching for survivors, myFOXphoenix.com reported.
Mr Babeu said 10 deputies had been dropped into the crash site from a helicopter to search for possible survivors. superstition mountains,
"We hope and pray [those on board] can be found safe and alive," he said, adding that officials from the Federal Aviation Administration (FAA) and National Transportation Safety Board were due to arrive at the crash site soon. mom arizona plane crash,
Footage broadcast live by the KSAZ-TV helicopter from the scene showed a large fire burning in the mountains, with several smaller fires nearby - all apparently sparked by the plane crash.
FAA spokesman Allen Kinitzer confirmed the plane that crashed was a twin-engine Rockwell AC69.
