It's stunning to see what a camera and a little investigation can do as is shown in a video created by Brooklyn-based filmmaker Dean Peterson.
The subway that Peterson uses everyday is Sunset Park's 36th Street and what sparked him to create this video was witnessing how common it was for everybody to trip on this particular staircase. From old to young, everybody seems to have trouble coming up the stairs. Upon more investigation, Peterson noticed that the tenth step was an inch taller than the rest and as a result he documented the whole falling fiasco.
After making this video, the MTA New York City Transit closed off the subways stairs to prevent accidents. The staircase is currently under construction thanks to a little curiosity and filmmaking talent by Dean Peterson.