Investigators are looking for hints as to why a vehicle travelling from the United States to Canada border accelerated prior to colliding and engulfing in flames.
The incident occurred on the Rainbow Bridge at the US-Canada frontier near Niagara Falls on Wednesday morning.
The couple in the vehicle died, and an agent of the United States border patrol was injured. Police reopened the bridge on Thursday evening while they investigated the incident.
On the eve of Thanksgiving, the accident initially caused a significant security concern, prompting authorities to close multiple ports of entry between Canada and the United States in the vicinity as a preventive measure.
Subsequently, New York Governor Kathy Hochul ruled out terrorism, but many unknowns remain, including the couple in the vehicle's identification.
Wednesday at approximately 11:30 local time (16:30 GMT), a detonation occurred, resulting in significant disruption on a highly travelled day preceding American Thanksgiving, which is among the busiest of the year.
Law enforcement in the United States confirmed that the two occupants of the vehicle were a married couple. It is unknown, however, as to why they plummeted.
The mayor of Niagara Falls, New York, Robert Restaino, stated to the New York Times that the couple were both in their fifties and business proprietors from the neighbouring island of Grand Island.
According to Mr. Restaino, they were travelling in an older Bentley model to Canada for what was believed to be a cancelled Kiss concert.
Police were investigating, among other possibilities, whether the vehicle's acceleration was the result of a mechanical malfunction, according to Mr. Restaino.
The Seneca Niagara Resort and Casino, situated on the New York side of the border and less than a mile from the Rainbow Bridge, has declared its cooperation with the ongoing police investigation. The casino was momentarily stopped when the vehicle passed through.
The Rainbow Bridge spans the Niagara River and serves as a pedestrian and motor vehicle crossing, connecting the Canadian city of Niagara Falls with the New York state of Niagara Falls.
Jim Diodati, the mayor of Niagara Falls, Canada, described the immediate aftermath of the explosion as a "emotional roller coaster" due to initial concerns of a terrorist attack and the difficulty for authorities in comprehending what had transpired.
The Buffalo branch of the Federal Bureau of Investigations announced in a statement that its investigation at the scene had been concluded.
No explosive materials were discovered, and no connection to terrorism was established.
As part of a traffic investigation, the Niagara Falls Police Department has been tasked with the matter.
The force stated that it was working to identify those involved and notify their next of kin, but "the investigation will take some time due to the complexity of the incident."
In the region, both Canadians and Americans have been impacted by the closure.
Although he was processing immigration documents on the American side of the border at the time of the explosion, which shook the ground in the US Customs and Border Patrol building where he was, Toronto resident Dor Tamang was an eyewitness.
Subsequently, he and an estimated dozen others were compelled to traverse the bridge on foot in order to return to Canada, while their vehicles remained on the United States side.