Investigators began documenting the wreckage of a plane crash in remote southwest Alaska that killed four people and injured six Friday night, the National Transportation Safety Board said.

The chief of the agency’s Alaska office, Clint Johnson, said an investigator with the NTSB and another from the Federal Aviation Administration reached the site Sunday where the single-engine aircraft went down near the village of St. Marys.

He said investigators will be at the accident site for a day or two. They will collect evidence and interview witnesses.

Johnson said it was too early to draw any conclusions about why the plane crashed. Another NTSB investigator in Anchorage also was hoping to interview survivors of the crash.

The Hageland Aviation Cessna 208 crashed about 6:30 p.m. Friday. It left Bethel on a scheduled flight for Mountain Village and eventually St. Marys but never reached Mountain Village.

The airplane would have been flying in freezing rain with a mile of visibility and a 300-foot ceiling, a spokeswoman for the Alaska State Troopers said Saturday.

Johnson said the plane was equipped with an advanced electronic locator transmitter that went off on impact and sent a satellite signal with GPS coordinates alerting officials to the accident.

St. Marys has about 500 people and is located 470 miles west of Anchorage. Like many Alaska villages, it is off the state road system. People routinely use small aircraft to reach regional hubs where they can catch another plane to complete trips to Anchorage or other cities.

Pilot Terry Hansen, 68, passengers Rose Polty, 57, Richard Polty, 65, and a 5-month-old infant, Wyatt Coffee, died in the crash.

The survivors included Melanie Coffee, 25, Pauline Johnson, 37, Kylan Johnson, 14, Tanya Lawrence, 35, Garrett Moses, 30, and Shannon Lawrence. All were seriously injured. All but Hansen and Shannon Lawrence are from Mountain Village, troopers said.

Melanie Coffee — whose infant son, Wyatt, died in the crash — walked nearly a mile toward lights in St. Marys to meet rescuers and led searchers hampered by cold and fog to the crash site.

“I believe she’s the real hero in this,” said St. Marys Village Police Officer Fred Lamont Jr., one of the dozens from his community and surrounding villages who responded to the crash.

Coffee, who suffered chest trauma, tried whistling to alert searchers, Lamont said. She considered starting a fire to get their attention but eventually decided to walk toward village lights. A GCI communications tower with a red strobe led her three-quarters of a mile to the village landfill.

“That’s where everyone found her,” Lamont said.