WASHINGTON - Family members of the people who perished when TWA Flight 800 went down off the coast of Long Island are dealing with fresh pain on the 17th anniversary of the tragedy, as a new documentary raises questions about the cause of the crash.

On July 17, 1996, a Boeing 747 carrying 230 people out of John F. Kennedy Airport broke apart mid-air, scattering debris across a 4-mile swath of the sea off of Moriches. A lengthy investigation into the Paris-bound flight by the National Transportation Safety Board concluded that the 747 blew up due to "an accidental spark igniting fuel vapors in the center fuel tank."

But a new documentary is challenging that conclusion. The film features interviews with six retired NTSB investigators who say they've uncovered new evidence that an "external explosion" delivered by a missile is what brought down the jumbo jet.

Hank Hughes, one of the former investigators, claims that eyewitnesses were threatened by government investigators. He says crucial evidence was tampered with or disappeared, and key scientific information, including radar, was ignored.

The claims are grabbing the attention of lawmakers on Capitol Hill. House Transportation subcommittee member Rep. Frank Wolf (R-VA) has fired off a letter demanding that the NTSB reopen the Flight 800 investigation. He wrote that the American people "deserve to know the complete, unvarnished truth."

In an interview with News 12 Long Island, Wolf said he asked the NTSB if there is new technology in 2013 that was not available in the weeks and months after the crash in 1996. The answer, he believes, is yes.

The NTSB says it reserves the rights to re-examine the findings of its investigation. But the former managing director of the agency, Peter Goelz, says the insinuations are nothing new. "I'm familiar with all of these individuals, I'm familiar with their work, and they're simply wrong," Goelz told News 12.

For victims' family members like Jim Hurd, who lost his son, Jamie, in the crash, it's just reopening old wounds. Hurd says he refuses to believe that the TWA disaster was anything but an accident. "I think we actually got the truth," he says.

The NTSB says it will take up to six months to decide if it wants to officially reopen the TWA investigation.