Amtrak is the national passenger railroad service in the United States, founded in 1971, and its locomotives use multi-chime air horns designed to be heard at grade crossings. The distinctive chord comes from a Nathan K5LA horn, a five-bell setup widely associated with American passenger trains. Recordings of these blasts circulate among railfans and editors who collect authentic railroad audio. Online, the clip moved beyond train spotting into memes and pranks, where the familiar warning blast signals an incoming train or an exaggerated, unstoppable arrival.