The Investigation is continuing into a helicopter crash that killed two people and injured another man Sunday near Smethport.

The Federal Aviation Administration is looking into the crash and the National Transportation Safety Board will determine the cause involving a McDonnell Douglas 600N helicopter that went down at 5:30 p.m. along East Valley Road in Keating Township.

Meanwhile, McKean County Coroner Mike Cahill identified the two deceased victims as Shane Filkins, 23, of West Virginia and Michael Koon, 35, of South Carolina. Cahill did not release any other details.

The sole survivor of the crash –– the pilot –– has not been publicly identified. He was transported to Bradford Airport by Priority Care Ambulance on Sunday, where Stat Med-e-vac landed to transport the patient. The patient was reported to have arm and leg fractures and be conscious during transport. The pilot was flying a helicopter from High Line Helicopters of Virginia.

“We’ve never been through this before. It’s tough,” said Tony Didado of J.W. Didado Electric of Akron, Ohio, owner of the company for which the men were working at the time of the crash.

The men were contractors working on power lines for First Energy.

Calling it “a terrible tragedy,” Doug Colafella of FirstEnergy said, “We don’t know what specifically had happened.”

The two workers who were killed in the accident had been supporting line construction of the Pierce Brook-Lewis Run Transmission Project, a 15-mile, 230-kilovolt power line between existing substations in Bradford and Keating townships.

“The new line is needed to maintain service reliability following the retirement of older power generating plants in the region, and is expected to be completed by mid-May, ahead of a June 1, 2018, in-service deadline,” Colafella said Monday afternoon. “When (Sunday’s) crash occurred, our contractors were using a helicopter to assist in stringing wires between the mostly wooden pole structures.”

Didado Electric has tackled quite a bit of work for FirstEnergy for the last 12 to 15 years –– or longer, Didado said. Workers had been part of that project since around December or January, he said.

“It’s been an ongoing project,” Didado said.

Colafella said that the practice has been used by utilities across the country for decades. This method reduces truck traffic, especially on private property and in rough terrain, he said.

“The helicopters are used to transport crews and materials (insulators, hardware and pulley blocks) to structures and to string, from structure to structure, the ‘pulling rope’ that will be used as a guide to install the conductors,” according to information from Colafella. “In order to facilitate the wire stringing process, pulling sites are established by the contractor in advance of the work. Pulling sites are gravel work area pads where the crews will set up pulling equipment that will guide the rope and conductor through the new transmission towers.”

Colafella said the method is better for the community by minimizing disruption to residents. The work is also more efficient, which significantly reduces the amount of time needed for stringing wires.

Colafella and Didado said such an incident is believed to have never happened before in the history of the two companies.

Peter Knudson, a public affairs officer with the National Transportation Safety Board, said details on what was found at the crash scene were not immediately available Monday, but he confirmed that the board is investigating.

Knudson described the process of investigations like these, which take several months.

The on-scene investigation is the shortest part, typically taking a few days, and is “focused on documenting perishable evidence,” he said.

Investigators look at the wreckage, talk to any witnesses, look for clues such as surveillance footage, listen to any communication recordings, such as air traffic or radio (contact) between crews on the ground and in the helicopter.

“We’re gathering all that would go away with the passage of time,” said Knudson.

A preliminary report is usually ready within one to two weeks of the start of the investigation, and then will appear on the NTSB website. That report will include facts and circumstances surrounding the crash, but it won’t include an analytical information or suggest a cause, Knudson explained.

In fact, it is usually one to two years before investigations come to a conclusion, he said.

“There’s a lot of work, of course, after the on-scene phase,” Knudson said.

That work, he said, can include tasks such as checking licenses, checking the 72-hour background of the pilot to determine if the person had time for sleep, checking the pilot’s medical history, looking into the pilot’s flight experience or testing aircraft components.

At the end, investigators lay all the information they’ve gathered out, determine the probable cause and decide “what role each of those items played in the accident,” said Knudson.

When asked how the information is used after the investigation concludes, he said it could end with a new safety recommendation. However, he noted that most helicopter accidents do not end with a new safety recommendation, as most don’t bring new issues that have not been seen before.

At that time, the investigation results are made public. Knudson noted that the report, the accident docket, interviews, photographs and other investigation information is posted to the NTSB website.

FirstEnergy will be reviewing safety procedures in determining its next step, Colafella said.