(CNN) -- The small plane had crashed in an extremely remote part of Alaska, miles from the tiny village of St. Mary's.
It was an especially dark and foggy Friday night, and rescuers were having a hard time figuring out the location of the Cessna wreckage and its 10 passengers.
They could hear survivor Melanie Coffee on the phone but with the poor weather, it was a frustrating needle-in-a-haystack kind of task.
But Coffee, 25, made her way a half-mile across the slippery, sloping tundra and managed to find the town's landfill, where she met the search party of 40 to 50 villagers and calmly guided them on foot back to the crash site.
For four people, including her 5-month-old boy, it was too late. They had died from their injuries.
The others had wounds that included head injuries and multiple fractures.
Had it not been for her going for help, more victims might have died, said Clifford Dalton, a paramedic for LifeMed Alaska.
"The fact that she could make it out to an identifiable landmark really helped to expedite the aid that the rest of the patients were able to receive," Dalton said. "What's really remarkable about it is that she was tending to her infant child that was gravely injured at the time."
The Anchorage Daily News reported that after the crash, Coffee used a cell phone to call the on-call health aide for St. Mary's, population 500. Fred Lamont Jr. told the newspaper Coffee was trying to give her infant son CPR.
Dalton called Coffee a hero who put the needs of others before her own.
Dalton said he and his partner, Paul Garnet, helped treat the patients at the site. Six to eight villagers helped carry each survivor to the landfill, which was as close as the ambulances could get. Concerned residents also came to help from Mountain Village, about 25 miles away, where most of the victims were from.
Authorities are unsure why Hageland Aviation Flight 1453 crashed. It left Bethel at 5:40 p.m. and went down about four miles from the St. Mary's airport.
"Hageland is working to gather information to answer questions and do what we can to ease the suffering of those involved in the accident. As a family-owned business this is an unspeakable tragedy for us," company president Jim Hickerson said on Hageland's Facebook page.
Authorities said the dead were Wyatt Coffee, 5 months; pilot Terry Hanson, 68; Richard Polty, 65; and Rose Polty, 57.
Four of those injured were hospitalized in fair condition, officials said. They are: Pauline Johnson, 37; Shannon Lawrence (age not given); Tanya Lawrence, 35; and Garrette Moses, 30. Also injured was Kylan Johnson, 14, who was treated and released.
A spokeswoman for the the Alaska Native Medical Center said Melanie Coffee was in fair condition and wasn't giving interviews.
The National Transportation Safety Board said Sunday it was too early to determine if weather was the cause.
Alaskans depend on air transportation far more than residents in other states because many villages aren't on the road system.
About 35% ofcommuter plane and air taxi crashes in the United States between 1990 and 2009 occurred in Alaska, according to data compiled by the Centers for Disease Control and Prevention.
By Steve Almasy
CNN's Paul Vercammen, Stan Wilson, Karan Olson and Joe Sutton contributed to this story.