Staten Island Hospital
OK, so I admit the link of this picture to the Tottenville Branch is tenuous–it is geographically far from Tottenville, but this is where the Tottenville Branch librarian (me) was born! Sadly, the building is unoccupied and in a very dilapidated state. After Staten Island Hospital moved to its new location (sometime in the late 1970s or early 1980s) this building was converted into an apartment building, but it went bankrupt after a few years. Some squatters occupied part of it a few years ago, but they were evicted. I think there are legal issues that keep it from being developed. It is a real eyesore in the neighborhood, which is very close to where I presently live.
(Picture from NYPL Digital Gallery)