An explosion of tremendous violence occurred at approximately 7:26 pm on Friday, May 19, 1950, at the Pennsylvania Railroad Pier No. 4 (Powder Pier) at the foot of Augusta Street, South Amboy (across inlet). This event was the result of the simultaneous detonation of 450 tons of military munitions. Two shipments, one of land mines and one of dynamite, were being transferred from railroad cars onto barges for subsequent loading onto the steamship Flying Clipper.
At 7:50 pm South Amboy Mayor John D. Leonard declared a state of emergency and requested help from Governor Alfred E. Driscoll. The state police and military assistance were quickly provided. Fire departments, first aid squads, and Red Cross disaster units, from as far away as Pennsylvania, poured into the stricken city. First aid field units were set up in the streets to provide emergency treatment while nearby hospitals accommodated the more seriously injured. Nearly every one of the 2,700 homes and buildings in South Amboy suffered some damage. Broken glass was extensive. Complete failure of electric power darkened the city. The death toll mounted to 31 with only five bodies identified and more than 350 persons injured. The citizens of South Amboy handled the ordeal remarkably well. Government specialists rushed to the area to access community impact and were greatly impressed by the city's response. The actual cause of the detonation is unknown to this day.
This Historic Marker is a gift to the people of South Amboy from the Middlesex County Board of Chosen Freeholders, 2013.