NIAGARA FALLS, New York (AP) — The FBI has ended its investigation of a fiery car wreck that killed two people at a border checkpoint in Niagara Falls after finding no evidence that it was a terror attack, easing a period of high tensions as Americans headed into the Thanksgiving holiday.

The FBI’s decision late Wednesday came several hours after the vehicle raced through an intersection, hit a median and was launched through the air before slamming into a line of booths and exploding at the Rainbow Bridge in Niagara Falls. Local police are now handling the case as a traffic investigation.

“A search of the scene revealed no explosive materials, and no terrorism nexus was identified,” the FBI’s Buffalo office said in a statement. “The matter has been turned over to the Niagara Falls Police Department as a traffic investigation.”

A spokesman for the City of Niagara Falls said the investigation has been taken over by the Niagara Falls Police Department’s Crash Management Unit.

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. The identities of those in the car have not yet been released.

The crash prompted the closure of the Rainbow Bridge and three other bridges connecting western New York and Ontario, as federal officials swarmed the area and both US President Joe Biden and Canadian Prime Minister Justin Trudeau received briefings. Hours later, officials sought to calm concerns on what is one the busiest travel days of the year.

“Based on what we know at this moment,” New York Governor Kathy Hochul said at a news conference, “there is no sign of terrorist activity in this crash.”

Hochul, a Democrat, said the car was “basically incinerated” with nothing left but the engine and a scattering of charred debris. Later Wednesday night, New York Sen. Chuck Schumer said investigators had found “no connection to any terrorist or criminal group. He added that there was no evidence of chemicals or substances used in explosives during investigators’ swabbing of the scene.

The Rainbow Bridge has about 6,000 vehicles cross it each day, according to the US Federal Highway Administration’s National Bridge Inventory.

Witness Rickie Wilson, a Niagara Falls tour guide, was by his parked car nearby and turned around when he saw something in the air.

“I first thought it was an airplane. It looked like slow motion,” he said. “I said, ‘My God, it’s a car. It’s a vehicle, and it’s flying through the air.'”