Six people on board a small twin-engine plane appear to have been killed when it crashed in a ball of fire on Wednesday in a remote area of the Superstition Mountains east of Phoenix, officials said.
Three of the presumed dead were believed to be children who were being flown to a town in Arizona for the Thanksgiving holiday, Pinal County Sheriff Paul Babeu told reporters.
There were no immediate signs of survivors among the six people thought to have been on the plane, which had refuelled shortly before it crashed and ignited a wildfire, officials said.
"At this point, we can't confirm there would be survivors. Our hope is that there would be, but it does not look promising," Babeu said.
The crash occurred in steep, cliff-like terrain near a remote summit in the Superstition Mountains called Flat Iron, said Elias Johnson, a spokesman for the Pinal County Sheriff's Office. That is about 45 miles (72 km) east of Phoenix.
The plane was identified as a Rockwell AC69 that took off from Falcon Field, in the Phoenix valley, said Allen Kenitzer, a spokesman for the Federal Aviation Administration.
The plane was registered to Safford, Arizona-based Ponderosa Aviation, an air charter firm. It has eight full-time pilots and has been in operation since 1974, according to the company's website.
"What we understand is that this aircraft flew from Safford to Falcon Field in Mesa (near Phoenix) to pick up children for Thanksgiving, to go back to Safford, so it's heartbreaking if that's the case," Babeu said.
Aside from the three children, the other people who were believed to be on board the plane were a pilot, a mechanic and another adult, Babeu said.