Missing F-35 jet was flying 'inverted' before crash, eyewitnesses say

WILLIAMSBURG COUNTY, S.C. — A South Carolina couple had been celebrating their son's 7th birthday on Sunday afternoon when they looked to the skies. A fighter jet was flying above them in an "inverted" position, they said, before they heard a "boom" moments later.

"Our kids always give a little salute, so we said, 'Look at the plane. Oh my gosh, it's so low,'" Adrian Truluck said. "And it was kind of probably 100 feet above the tree tops, and almost going inverted."

"It was probably three quarters of the way," added her husband, Stephen Truluck, as he gestured with his hand. "We could see the canopy" of the plane.

They didn't think much of it at the time, they said, because Shaw Air Force Base is about 60 miles away. But after learning an F-35 fighter jet had gone missing — and that a debris field was found Monday just miles from their home in rural Williamsburg County — they realized what they saw likely wasn't just any aircraft.

Capt. Joe Leitner, a spokesperson for the 2nd Marine Aircraft Wing, declined to comment on the Trulucks' account and other details in order to "preserve the integrity of the investigatory process," which remains ongoing.

The incident drew attention Sunday afternoon when Joint Base Charleston, located about 80 miles south of Williamsburg County, asked the public for help finding a missing F-35B Lightning II jet.

The jet's pilot had "ejected safely" just before 2 p.m., but the military said it could not locate the F-35, which is known for its stealth mode capabilities, because its transponder did not appear to be working.

It wasn't until more than 24 hours later when the base announced a debris field had been located in Williamsburg County.

Questions remain as to why the pilot ejected from the aircraft and why the jet appeared to have continued flying undetected.

After initially saying the jet had been left in autopilot when the pilot ejected from the aircraft, Jeremy Huggins, a spokesman at Joint Base Charleston, later told NBC News that authorities did not know whether that was the case and were still investigating.

The Trulucks said they did call the military on Monday afternoon to report what they had seen the day before, but believe authorities had likely already zeroed in on the crash site.

They said the jet would have flown over a sunflower field, trees and a few houses along their road before crashing. No injuries were reported on the ground.

The couple added that they heard a subtle "boom" noise following the sighting of the jet but figured there was a simple explanation: the stormy weather.

"We were thinking it was rolling thunder in the distance and didn’t give it another thought until we saw the plane was missing," Adrian Truluck said, "and we were like that had to be the plane."

Sam Brock reported from Williamsburg County, and Erik Ortiz from New York.

This article was originally published on NBCNews.com