I think you're right, its something on the order of the NY State (downstate) Correctional facilities at Sing Sing ... but the prison has always been known Sing-Sing. The town got tired of giving their name to the prison, so they changed it to Osinging-- both names came from indian place names for area.

But it was where you went, in James Cagney movies when you got sent "up the river"-- which is still used to express prison time.