Rescuers found four plane crash survivors -- including three young boys and their father -- in a snowy state forest Monday where they had endured a night in the bitter cold. Three other family members were killed when the plane went down the day before, and the father later died in a hospital.

A state police helicopter combing the mountainous region spotted someone waving from the crash site at midday Monday. Three were taken out by helicopter; a fourth was transported by snowmobile.

"I'm totally amazed. They're very, very tough to have made it through the night," said Richard Toman, state police civilian search and rescue administrator. "This is the stuff movies are made of."

Police Sgt. David Paine confirmed three others were killed in Sunday night's crash. The dead were not immediately identified, but it was believed the plane was carrying a couple and their five boys, ages 2 to 11.

Ronald Ferris, the father, was taken to Fairview Hospital in Great Barrington for treatment of hypothermia and cardiac arrest, a hospital spokeswoman said. He was pronounced dead just before 9 p.m.

Albany Medical Center Hospital said Ryan Ferris, 2, and 5-year-old Jordan Ferris were being treated for hypothermia. Tyler Ferris, 10, was being treated for hypothermia and a broken leg. All three boys were in critical condition.

State Police Lt. Marion McGovern said the plane was found in about 4 feet of snow with two people trapped inside. It was spotted in Beartown State Forest, a mountainous area near the Connecticut and New York state lines.

New York state police helicopters had to drop rescuers into the area to stabilize the survivors before flying them to the hospital, Paine said.

"They were frozen," said Peter Berry, a deputy chief of Colonie, N.Y., Emergency Medical Services, who was riding in the helicopter.

Temperatures in the mountains were in the single digits early Monday with gusty 15 mph to 30 mph wind. Search teams on the ground had been fighting their way through snow up to 4 feet deep.

The single-engine Piper Cherokee Six disappeared on a flight from Harrisburg, Pa., to an airport near Keene. Flight controllers lost radio contact with the pilot Sunday evening.

The pilot had reported that he was having problems with icing, said Jim Peters, a spokesman for the Federal Aviation Administration.

Peters said tapes showed the plane disappeared from radar at an altitude of about 2,200 feet some 9 miles east of the Great Barrington Airport, while headed straight for that airport.

Acquaintences said the family from Keene, N.H., owned a car dealership and were known locally through their radio advertisements, which sometimes featured the boys' voices.

Peter Dower, an employee at Ferris' used car business in Swanzey, said Ferris had been piloting a plane carrying his wife and five sons and that they had been returning from a vacation in Florida.