There was a serious accident on the site on October 15, 1904, when, during practice, a charge went off without the breech of the mortar being fully closed. Four men were killed and nine others were seriously injured. Later, anti-aircraft guns were added and the Fort became the base for the Army's 9th Artillery Regiment. It also had a 250-bed hospital. In the 1950s Nike anti-aircraft rockets were based on the site. Of the four pits, only one, Mortar Pit B, remains, together with two underground bunkers leading off the pit. It was added to the National Register of Historic Places in 2007.