The Hercules Powder plant disaster was an explosion at an armaments factory owned by the Hercules Powder Company in the Kenvil section of Roxbury, New Jersey, on 12 September 1940. About 52 people were killed and 100 injured.
The cause of the explosion remains unclear. Possible explanations include an industrial accident or sabotage carried out by the Irish Republican Army (IRA) or by a group of German Americans living in nearby Sussex County. After German immigrant Oscar C. Pfaus helped connect Nazi agents with the IRA in America, Abwehr agent Karl Franz Rekowski was sent to the U.S. where he arranged for the IRA to carry out sabotage attacks. Rekowski alleges the IRA carried out the attack on the plant.
The 1940 explosion at the Hercules factory followed another in 1933 that killed six people; in 1989, a third explosion there shattered windows across the town.
- Petriello, David. (2014). Military History of New Jersey. Charleston: History Press. p. 123. ISBN 978-1-62585-158-1.
- Petriello, David (2014). Military History of New Jersey. History Press. pp. 157–158. ISBN 978-1626196278.
- "Ethnic Germans as an Instrument of German Intelligence Services in the USA, 1933-45" by Cornelia Wilhelm in Heike Bungert, et al. (Eds.) (2003). Secret Intelligence in the Twentieth Century. London: Frank Cass. pp. 48. ISBN 978-0-7146-5395-2.
- Hochman, Louis C. "Long-vacant Hercules plant site could get transit village, warehouses", NJ Advance Media for NJ.com, September 15, 2014. Accessed July 21, 2016. "Hundreds of residents manufacturer high explosives at the Hercules Powder Factory, according to the Roxbury Township Historical Society. Two explosions killed six workers in 1934. Then, in 1940, more than 297,000 pounds of gunpowder blew up at the factory in a series of explosions and fires, leveling 20 buildings in the nearby area. That explosion killed 51 people and injured and burned 200 others, according to the historical society."