In June, 1892, the USS Boston, a protected heavy cruiser, was at Mare Island for maintenance. Rather than let the sailors of the Boston go on leave, they were put to work at the ammunition depot without proper training and probably without proper equipment. Fifteen men, all sailors from the USS Boston, died in an explosion at the Naval Ammunition Depot on June 13, 1892.

The sailors had been preparing the shells for the Boston at a magazine in the ammunition depot when the explosion occurred at about 11:30 p.m. The cause of the explosion remains murky, but the aftermath was well recorded. A dozen men died instantly, one blasted through the magazine roof to land on another. Three more, including the two who were found charred and skinned on a beach, died slowly. The Navy immediately went into action to douse the flames before they set off other explosions. By the next afternoon, the graves had already been dug for the 15 men. There was a special ceremony honoring them in 2010, the 118th anniversary of their deaths.