— A vehicle speeding toward a U.S.–Canada bridge from the American side crashed and exploded at a checkpoint in Niagara Falls on Wednesday, killing two people and prompting the closing of multiple border crossings for hours. Authorities weren’t sure what spurred the wreck but said there were no signs it was a terror attack.

Much remained unclear about the incident at the Rainbow Bridge, which stirred concerns on both sides of the border as the U.S. headed into the Thanksgiving holiday. Both U.S. President Joe Biden and Canadian Prime Minister Justin Trudeau were briefed soon afterward, and Trudeau excused himself from Question Period in the House of Commons to get further information, saying officials were “taking this extraordinarily seriously.”

A few hours later, New York Gov. Kathy Hochul and western New York’s U.S. attorney, Trini Ross, both sought to ease fears, while cautioning that the investigation was in the early stages.

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

At a separate news conference with Ross nearby in Buffalo, Erie Country Sheriff John Garcia said, “We can go on with our lives.”

Security camera video released by U.S. Customs and Border Protection showed the car racing through an intersection, hitting a low median and vaulting into the air in a U.S. Customs and Border Protection area just east of the main vehicle checkpoint. The car flew for yards (meters), twisting, and then crashed out of the camera’s view.

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.’”

The identities of those in the car weren’t released. Hochul said it wasn’t clear whether the driver — a western New York resident — was intentionally heading for the bridge, which crosses the Niagara River.