Odd...I could have sworn that happened near New Jersey.
Near Pittsburg, California:
http://www.history.navy.mil/faqs/faq80-1.htm
"As war in the Pacific expanded, the Naval Ammunition Depot at Mare Island, California, was unable to keep up with the demand for ammunition. Port Chicago, California, located 35 miles north of San Francisco, proved an ideal place for the Navy to expand its munitions facilities."
"On the evening of 17 July 1944, the empty merchant ship SS Quinault Victory was prepared for loading on her maiden voyage. The SS E.A. Bryan, another merchant ship, had just returned from her first voyage and was loading across the platform from Quinault Victory. The holds were packed with high explosive and incendiary bombs, depth charges, and ammunition - 4,606 tons of ammunition in all. There were sixteen rail cars on the pier with another 429 tons. Working in the area were 320 cargo handlers, crewmen and sailors.
At 10:18 p.m., a hollow ring and the sound of splintering wood erupted from the pier, followed by an explosion that ripped apart the night sky. Witnesses said that a brilliant white flash shot into the air, accompanied by a loud, sharp report. A column of smoke billowed from the pier, and fire glowed orange and yellow. Flashing like fireworks, smaller explosions went off in the cloud as it rose. Within six seconds, a deeper explosion erupted as the contents of the E.A. Bryan detonated in one massive explosion. The seismic shock wave was felt as far away as Boulder City, Nevada. . . .
"All 320 men on duty that night were killed instantly. The blast smashed buildings and rail cars near the pier and damaged every building in Port Chicago. People on the base and in town were sent flying or were sprayed with splinters of glass and other debris. . . . The blast caused damage 48 miles across the Bay in San Francisco."
Probably two different incidents. There were many during WWII. There was another at one of the Great Lakes ports also.
Naaaa ............ New Jerk has always lookt like dat.
The New Jersey incident (at Black Tom Island, in Jersey City) was in World War I, but while the U.S. was still neutral. It was probably German sabotage, but exactly who did it was never determined.