HONOLULU -- A couple who survived a fatal helicopter crash on Kauai two months ago said Friday that they will cooperate in the homicide investigation targeting the chopper's pilot.

It's the first time prosecutors in Hawaii have opened a criminal investigation into a fatal air crash.

When the Heli-USA tour helicopter crashed in the ocean off Kauai's North Shore on Sept. 23, three passengers died, including Laverne Clifton, 68, who was on Kauai celebrating his 45th wedding anniversary.

His son-in-law, Bill Thorson Jr., and his daughter survived the crash. Thorson said he has heard from Kauai prosecutors.

"They have contacted us and they want to talk to us, and we told them we'd give them our full assistance in this," he said.

Prosecutors are initially targeting pilot Glen Lampton, who also survived the crash. In a rare move, they're looking at possible negligent homicide or manslaughter charges against Lampton.

"I think it would have been a lot better for him if he would have just said, 'Well, I made a mistake and flew into that storm,'" Thorson said.

Thorson, his wife and other helicopter pilots in the air at the time said Lampton's claim that he flew into a bad thunderstorm to avoid another chopper is untrue. They said the other chopper was far away.

"We want to know why, why it happened and could it have been prevented and did three people have to die that day? We're starting to think, 'No they didn't,'" Thorson said.

A Heli-USA spokesman said the pilot, who had been flying choppers on Kauai for only six or seven weeks, has since moved off the island. The spokesman said Lampton is still working for the company, but is not flying until the investigation is over.

Asked if he and his wife would fly back from Wisconsin to testify if the case went to trial, Thorson said, "Yes, we would. We'd hate to fly back, to tell you the truth, but if that's what it takes, then we will do that."

"I think about that crash and that flight two or three times a day," he said. "Not a day goes by that I don’t relive that flight."

Bill Thorson works in a rubber and plastics factory in Burlington, Wisc. His wife, Karen, is a police evidence technician in Beloit, Wisc.

The only known criminal prosecution in an aviation disaster happened in Florida, after a Valujet plane crashed in the Everglades nine years ago, killing 110 people aboard.

The state attorney's office in Miami-Dade went after SabreTech, the company, which processed oxygen containers investigators believed caused the fire that led to the crash.

SabreTech was charged with 110 counts of murder, manslaughter and other charges, said Gary Winston, the assistant Florida state attorney who handled the case.

In the end, Winston said, SabreTech pleaded guilty or no contest to a single count of unlawful transportation of a hazardous waste. The company agreed to pay a $500,000 penalty to help air crash victims, he said.

Half of the money went to the National Air Disaster Alliance, a group that supports survivors and next of kin of air crash victims, according to Winston.

"It took a huge amount of time and resources to prepare this kind of case," Winston said.

He said criminal prosecutions in fatal air crashes are rare because "certainly for most local prosecutors' offices, it's much too big to be done on a routine basis."

"We have a volume practice, and most prosecutors are busy all the time," handling routine crimes with which they are more familiar with, Winston said. But air crashes involve different federal laws, regulations and agencies, including the National Transportation Safety Board and the Federal Aviation Administration, which prosecutors must spend time learning about, he said.

"We never would have been successful without the assistance of the United States Environmental Protection Agency, who gave us technical and financial support in our case. Their agents were influential in helping us, so we had a large partner, and it worked out," he said.

The FAA has pledged to help Kauai prosecutors if they bring a criminal case in the chopper crash.