An air ambulance plane taking a heart disease patient to a Utah hospital has crashed and exploded in a car park in northern Nevada, killing all four people aboard.
Three crew members and a patient were killed in the Friday night crash in Elko, American Medflight said.
The victims were pilot Yuji Irie, medical staff members Jake Sheppard of Utah and Tiffany Urresti, 29, of Elko, and patient Edward Clohesey, of Spring Creek, Nevada.
Ms Urresti was a volunteer firefighter in Elko, Elko police chief Brian Reed said, adding that her death "hit pretty close to home".
Elko police Lt Rich Genseal said the twin-engine plane apparently "experienced mechanical problems" as it was climbing after taking off on a flight for Salt Lake City, then lost altitude and crashed.
The twin-engine plane crashed in a mining company's car park near a casino and other businesses near Elko Regional Airport and the Interstate 80 road.
American Medflight president John Burruel said the company is cooperating with the National Transportation Safety Board and the Federal Aviation Administration as they investigate the crash.
"As an air medical family, we are mourning the loss of our crewmembers and patient. Their families have been notified, and they are in our thoughts and prayers," Mr Burruel said.
Tiffany Urresti's parents said she was a former hospital ER nurse who dreamed for years of working as a flight nurse.
Ms Urresti achieved her dream, starting work for American Medflight two months ago, and she was engaged to be married in May, Debibi Urresti said. "She found the love of her life."
Federal Aviation Administration spokesman Allen Kenitzer said no-one on the ground was hurt.
"There was not a lot left of the aircraft," Elko Fire Chief Matt Griego said after the flames were extinguished.
A photograph published by the Elko Daily Free Press showed mostly burned wreckage on pavement in front of a line of vehicles, including at least one charred pickup truck. The plane's tail was one of the few recognisable parts.
Hillary Walker, a manager at a grocery store about 200 yards from the crash, told the Las Vegas Review Journal that the crash caused parked vehicles to catch fire, before dozens of rounds of ammunition went off.
Ms Walker noted that said a number of vehicles in the parking lot for mine workers likely had ammunition in them. "It's hunting season out here," she said.
Dr Rodney Badger of Northeastern Nevada Cardiology said the plane had just taken off from the nearby airport to transport a patient to the University of Utah Medical Centre.
Dr Badger said his patient suffered from coronary artery disease and was experiencing chest pains and rapid heartbeat around 5.30pm, after which the decision was made to transport him to Utah.