The rusted seats that washed up on the New Jersey beach came four abreast, bound together in a metal frame, as if they had come from an airliner cabin.
And when the discovery was posted on TikTok last week, many people speculated that the seats were wreckage from some past aerial catastrophe.
But on Thursday local police said they believed the seats had a more prosaic origin: an old train carriage dumped in the ocean, possibly to help build up a nearby artificial reef.
“The seats are far too heavy to have come from anything like a plane,” said Margate city police chief Matthew Hankinson, according to NJ.com.
The seats were first discovered last Tuesday morning on the Quincy Street beach by Matthew J Perry, a local actor who has about 14,000 followers on TikTok under the name Matthew Jacob.
"I think I just found plane seats washed up on the Jersey shore," said Mr Perry in a video that was liked 1.4 million times. "Must have been from a really long time ago."
Over the next week, Mr Perry reported his find to the police and enlisted help from his followers to solve the mystery, prompting many inquiries from journalists.
Some TikTok users speculated that the seats could have come from Malaysia Airlines Flight 370, which famously disappeared over the Pacific Ocean in 2014.
Others suggested, more realistically, that it could be from Trans World Airlines Flight 800, which exploded off the coast of New York in 1996 – a theory that Mr Perry himself found persuasive.
Still others made jokes, saying the seats must be "the airport shuttle at Newark Airport [that] I’m still waiting for", or claiming they were from "a 2011 Kia Soul".
When detectives and public works officials examined the seats, however, they found no indications that the seats had come from a plane.
“The seats are stripped down to the metal with nothing left from cushions, seat belts or buckles that would indicate they came from a plane crash,” said Margate police spokesperson Lt Joe Scullion said.
“A detective did some further research and found that decommissioned railcar seats are typically stripped down to the metal parts and taken out to sea and dumped to help build artificial reefs.”
On Wednesday Mr Perry updated his followers again following a conversation with officers. "They said it's either a train [or] a bus... they dumped them in the Seventies or Eighties – artificial reefs," he said. "So there you have it."
