Charles T. Harvey finished building the West Side and Yonkers Patent Railway elevated line up Greenwich Street in 1867. Here's how he tested it out.
That line ended up becoming the 9th avenue elevated line, which became known for having the worst accident in the history of NYC's elevated lines. In 1905, one train left the tracks on the sharp curve on 53rd street, where the 9th Ave line met up with the 6th Ave line.
Thirteen people died and 48 were seriously injured due to one train being mistakenly sent down the wrong track.
Photo Credit: Columbia University