A speeding car crashed in flames on the bridge linking New York state and Ontario at Niagara Falls on Wednesday, killing two people in the vehicle and sparking a security scare that closed four U.S.-Canadian border crossings and Buffalo International Airport.

Hours later federal and state authorities said investigators had found no evidence of an act of terror, though circumstances surrounding the episode on the Rainbow Bridge remained murky, leaving it yet to be determined whether the crash was accidental or intentional.

"At this time, there is no indication of a terrorist attack," New York Governor Kathy Hochul told reporters Wednesday evening. Her comments were echoed a short time later by federal law enforcement officials at a separate news conference.