Four people were critically injured in a plane crash near the summit of Atigun Pass in northern Alaska on Sunday, the Alaska State Troopers reported.
Troopers and the National Transportation Safety Board said Alyeska Pipeline Service Company security guards first reported the crash around 1:45 p.m.
The plane was reported to have crashed near Mile 243.5 of the Dalton Highway, Alaska State Troopers spokeswoman Beth Ipsen said Sunday evening.
The four injured are believed to have been the only people on the aircraft.
The crash happened in an area that's part of the North Slope Borough, she said. Borough emergency responders will be taking over the incident response. According to Ipsen, the area of the crash is accessible from the road and allowed first responders to reach the scene.
"Alyeska Pipeline Service personnel responded with medics and were able to retrieve the injured people and get them to a nearby airstrip," Ipsen wrote in an email.
A wildlife trooper flying a patrol in the area was able to land later in the afternoon, Ipsen said, but the injured passengers had already been picked up by air ambulance by the time he arrived.
"The communications are really spotty. He could relay information, where it was, and the number of people injured," she said.
The four passengers had not been identified as of Sunday evening.
Clint Johnson, head of the NTSB's Anchorage office, said it was too early to say what type of plane crashed, who owned it or what it may have been doing flying in the area.
Johnson said the NTSB will investigate the crash, but details were still coming out slowly Sunday evening.
"It's just a waiting game at this point," he said.
This is a developing story. Check back for details.