Largest homeland disaster during World War II On the evening of July 17, 1944, residents in the San Francisco east bay area were jolted awake by a massive explosion that lit up the night sky. At Port Chicago Naval Magazine, 320 men were instantly killed when the munitions ships they were loading with ammunition for the Pacific theater troops blew up. On October 28th, 2009, Port Chicago Naval Magazine National Memorial became the 392nd unit of the National Park Service.