A vehicle speeding toward a US-Canada bridge from the American side crashed and exploded at a checkpoint in Niagara Falls, killing two people and prompting the closing of multiple border crossings for hours.
Authorities were not sure what spurred the wreck but said there were no signs it was a terror attack.
Remarkable CCTV video showed the vehicle hurtling towards the border crossing before launching into the air before crashing and bursting into flames.
CNN reported the driver was a 56-year-old man who was traveling in a $300,000 Bentley with his wife to attend a concert by the rock group KISS.
The FBI's Buffalo office said late on Wednesday that it had concluded its investigation: "A search of the scene revealed no explosive materials, and no terrorism nexus was identified," it said in a statement.
"The matter has been turned over to the Niagara Falls Police Department as a traffic investigation."
Much remained unclear about the incident at the Rainbow Bridge, which prompted concerns on both sides of the border as the US headed into the Thanksgiving holiday.
Both US President Joe Biden and Canadian Prime Minister Justin Trudeau were briefed soon afterwards, and Mr Trudeau excused himself from a question period in the House of Commons to get further information, saying officials were "taking this extraordinarily seriously."
Footage from CCTV Cameras showing the Explosion of a Car at “Rainbow Bridge” Custom’s Checkpoint in Niagara Falls on the Border between Canada and the United States after the Vehicle can be seen Striking a Curb and going Airborne; the Incident was initially believed to have… pic.twitter.com/OirbU4M8JY
— OSINTdefender (@sentdefender) November 22, 2023
A few hours later, New York Governor Kathy Hochul and Attorney for the Western District of New York Trini Ross both sought to ease fears.
"Based on what we know at this moment," Ms Hochul said at a news conference, "there is no sign of terrorist activity in this crash."
At a separate news conference with Ms Ross nearby in Buffalo, Erie Country sheriff John Garcia said, "We can go on with our lives."
Security camera video released by the US government showed the car race through an intersection on a wet road, hit a low median and vaulted high into the air in a US Customs and Border Protection area just east of the main vehicle checkpoint.
The car flew for yards, twisting, and then crashed into a line of booths out of the camera's view.
The identities of those in the car were not released. Ms Hochul said it was unclear whether the driver - a western New York resident - was intentionally heading for the bridge that crosses the Niagara River.
The two people who died were a husband and wife, according to a person briefed on the investigation who spoke to The Associated Press on condition of anonymity because they were not authorised to release information about the people who were killed.
Matthew Miraglia, the FBI special agent in charge in Buffalo, said investigators had found no "derogatory" information on the driver.
"We're scanning his social media. There's nothing there," Mr Miraglia said.
New York senator Chuck Schumer said on Wednesday night that he had been in contact with both the FBI and the White House, and investigators had found "no connection to any terrorist or criminal group."
Investigators swabbed the scene and found no evidence of chemicals or substances used for explosives, he added.
Officials said the car was travelling at a tremendous speed as it approached the bridge at around 11:30am in downtown Niagara Falls in an area that includes several hotels and a casino.
Ms Hochul said the car ended up "basically incinerated," with nothing left but the engine. Debris was scattered across a dozen checkpoint booths.
The governor, a Democrat, called video of the airborne car "absolutely surreal."
Photos and videos taken by bystanders and posted on social media showed thick smoke, flames on the pavement and a singed security booth.
A Customs and Border Protection worker in a checkpoint booth was treated at a hospital for minor injuries and released, Ms Hochul said.
