Two people were killed and two others remained missing in a medical plane crash in Northern California, authorities said Friday.
The plane, which vanished over the small Pacific coast community of Arcata, was located on the property of a private timber company in Cranell, about 12 miles north, said the Humboldt County Sheriff's Office. The two dead were not immediately identified.
The pilot of the plane radioed an emergency at around 1 a.m. PT (4 a.m. ET) when smoke filled the cockpit, said Federal Aviation Administration spokesman Ian Gregor. The dual-engine Piper PA31 disappeared shortly thereafter.
Parent company REACH Air Medical Services said the plane was carrying a pilot, flight nurse, transport medic and patient when it went missing about 5 miles northeast of the Arcata-Eureka Airport. The current location of the other two passengers was unknown.
The plane was headed from the northern town of Crescent City to Oakland, a 360-mile trip. Before the plane went missing, the pilot reported that he planned to return to Crescent City.
Don Wharton, spokesman for Cal-Ore Life Flight, which provides the service through REACH, could not immediately provide information about the staff members on board.
"All pilots come to us with vast amount of experience, the average being well over 3,000 hours of air carrier flying time," he said in a statement. "These are all highly skilled professionals."
The debris field from the crash site spans a quarter of a mile and has been secured, the county government said. The National Transportation Safety Board is sending personnel to investigate the crash, the county said.