Transportation authorities are determining what struck a high-speed Amtrak Acela train as it passed through Philadelphia on Sunday night.
Just before 7 p.m., a northbound Acela headed from Washington, D.C., to New York City suffered a cracked window after it was mysteriously struck by an object as the train passed through Philadelphia’s Bridesburg neighborhood, ABC reported.
“There was this giant boom. It almost sounded like this tray table had dropped really hard and strong and loud,” passenger Taylor Lorenz told CBS in a related article. “Immediately everybody looked at it and said, ‘Oh my God, it’s a gunshot. Is thata bullet in there? What’s going on?’”
Images posted on social media showed the damaged window after it had been struck.
Close up of the bullet hole pic.twitter.com/SiWWWYi8Sk
— Taylor Lorenz (@TaylorLorenz) February 1, 2016
The train was later stopped at the Metropark station in New Jersey so inspectors could check for other damage, ABC added. There was none, and the train continued to its destination, New York’s Penn Station.
No crew members or passengers were injured in the incident, according to CBS.