NIAGARA FALLS, N.Y. (AP) — A police investigation into the crash and explosion that killed two people in a high-powered luxury car at a Niagara Falls border crossing last year has concluded with the crash’s cause still a mystery, authorities said.

The probe into the Nov. 22, 2023, crash that killed Kurt and Monica Villani, both 53, “is considered closed at this point, but can be reopened if any new evidence comes to light,” Niagara Falls Mayor Robert Restaino told The Buffalo News this week.

Restaino said investigators were hampered by the fact that the car’s event data recorder, or black box, was destroyed in the crash.

The Villanis, who were from the western New York community of Grand Island, were in a 2022 Bentley Flying Spur that crashed and exploded at the Rainbow Bridge connecting the cities of Niagara Falls, New York, and Niagara Falls, Ontario, Canada.

Security camera video showed the Bentley race through an intersection, hit a low median and vault high into the air just east of the bridge’s main vehicle checkpoint. The car flew for yards (meters) and crashed into a line of checkpoint booths outside the camera’s view.

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The violent crash at the U.S.-Canada border aroused fears of terrorism, but the FBI’s Buffalo office said its investigation found no signs of a terror attack and turned the case over to local police.

The Niagara Falls police investigated the crash without finding any answers to questions such as whether a mechanical failure or driver error was to blame, the newspaper reported.

Calls to the Niagara Falls police placed by The Associated Press were not returned, and a staff member in Restaino’s office said the mayor was not available to speak on Wednesday.

Restaino told the Buffalo News that no one may ever know what caused the crash unless insurers discover it.

A message seeking comment was sent to the Cincinnati Insurance Companies, identified by authorities as the company that insured the Bentley.

Erin Bronner, a Bentley Motors spokesperson, told the Buffalo News last February that Bentley Motors was conducting its own investigation into the fatal crash.

Bronner declined to discuss any details of the case on Wednesday.

Police said the Villanis were killed instantly in the crash and pronounced dead at the scene. The Edmunds.com website describes the 2022 Flying Spur as a high-powered luxury car that can go from 0 to 60 miles (96 kilometers) per hour in four seconds. When new, the vehicle sold for $204,500 to $309,000, depending on which options were purchased, the website said.