Exit 6, at 15th Street, formerly passed through a Con Edison substation, which handles most of the electricity for lower Manhattan. It was closed after the September 11, 2001 attacks after city and ConEd officials concluded it was too risky to allow such easy access to such a critical piece of infrastructure. The exit was permanently removed in 2014 after the New York State Department of Transportation received notification from the New York City Police Department that the exit would not be re-opened since the ConEd facility was deemed a potential terrorist target. East 15th Street, as well as a corresponding entrance ramp from 14th Street, were also closed east of Avenue C, except to ConEdison and law enforcement vehicles. All signage of exit 6 was removed in early 2016.