The two passengers who died in an Angel Flight crash in upstate New York were a cancer patient and his wife, a volunteer pilot said Sunday.

Authorities investigating the crash of the twin-engine aircraft that went down Friday evening in Ephratah, a small town about an hour west of Albany, returned to the site Sunday to scour the woods and a nearby pond for the missing pilot.

Terence Kindlon, an Albany attorney who is a volunteer pilot for Angel Flight, said he and another lawyer had flown the cancer patient and his wife to Boston on Friday morning. Kindlon, 66, said the husband was being treated for glioblastoma, a type of brain cancer. He said they seemed like a happy pair.

"We were both former Marines and had been in Vietnam pretty close together in time," Kindlon said. "We hit it right off. He was a nice guy."

He did not name the couple since authorities have yet to reveal their identities. Their bodies were found Friday near the crash site, Fulton County Sheriff Thomas Lorey said.

National Transportation Safety Board investigators that returned to the crash site Sunday aim to retrieve the bulk of the wreckage from the water over the next few days, said agency spokesman Eric Weiss. They are looking for smartphones, GPS devices, computer tablets or other items that could "give the investigators some electronic evidence of what happened in the last minutes of flight," he said.

Wreckage from the crash was dispersed over a large area, with pieces of the plane found as far as 5 miles away.

Plans called for rescue workers to canvass the woods and divers to use sonar to search a big, murky pond where the bulk of the aircraft was submerged. Town Supervisor Todd Bradt has said divers had trouble seeing in the water because it's so muddy, but a piece of the plane was removed earlier.

Angel Flight is a nonprofit group that arranges free air transportation for sick patients from volunteer pilots. Larry Camerlin, president and founder of Angel Flight Northeast, said the organization was "tremendously saddened" by news of the crash.

While the cause of the crash remains under investigation, Kindlon stressed that "the standards for being an Angel Flight pilot are rigorous."

The Piper PA 34 had departed from Hanscom Field in Bedford, Mass., and was headed to Rome, N.Y., before it crashed just after 5 p.m. Friday, Federal Aviation Administration spokeswoman Kathleen Bergen said. The plane did not issue a distress call before losing radar and radio contact, the NTSB said.

Visibility at the time in Rome was 10 miles, said National Weather Service meteorologist Brian Montgomery. It was slightly raining with winds of 13 to 14 mph.

Witnesses described the destruction that started in the air above Ephratah, a sleepy town of about 700 people.

Joan Dudley, owner of Granny's Ice Cream Shanty, which is less than a mile from the crash site, said she and her employees were among the first at the scene Friday night.

"We looked up and saw the plane flipping in the air. Then it fell apart," she said. "Parts and pieces of it were flying through the sky, and a body fell out."

They called 911 as they parked their car and ran to the crash site in the rain to see if they could rescue anyone.

"Airplane parts were all over the place," she said. "They were picking them up all over."

Ephratah resident Roger Berry, 75, said he was outside chopping wood when the plane crashed.

"When I heard it, I knew something was wrong," Berry said. "It made one circle and came back around."

Berry said he heard a bang, then saw pieces of the plane fall from the sky and scatter. The motor fell 50 feet from his neighbor's bedroom, where she was sleeping, Berry said.

Angel Flight Northeast said it has set up free air transportation and medical care for more than 65,000 children and adults on about 60,000 flights covering more than 12 million miles. It was founded in 1996.