The massive explosion on July 17, 1944, at the little-known Bay Area Navy base named Port Chicago, might not even register on the history radar for most people. But for William Ross, 92, the disaster is still as close as a cup of coffee.

As the 75th anniversary rolls around this July, Ross is one of the few survivors left to tell the tale of that tragic day — a story that illuminated the mass racial disparity in the military of the time — a colossal tragedy compounded by its aftermath.

Family, friends and fellow sailors marked the somber anniversary of the Port Chicago explosion that killed 320 mostly African American men. Jodi Hernandez reports.

Ross was in his barracks that night, just stepping out of the shower — about a mile from the piers where he and other black sailors would unload torpedoes, bombs and depth charges from train cars, and load them onto military ships destined for the war.

Their training was haphazard, Ross remembered. From his fellow sailors to the white officers. Even a single bomb carried the potential for a harrowing amount of devastation. The warships the sailors loaded were filled with them.

The Port Chicago Disaster: 75 Years Later

"You loaded the ammo on the boat and it was a terrible thing," Ross recalled over the kitchen table in his Santa Ana apartment. "You wondered is this it? Is this it? Is it going to explode?"

The answer to that question came sudden and violent.

At around 10 p.m. two ships sat at the dock -- the Bryan and the Quinault Victory. The Bryan was loaded down with ammunition and bombs, ready to ship out the next morning. Ross felt the blast. Was it an earthquake? The barracks rocked, the windows blew out, lodging glass into his bare legs.

"Everybody started running, we were running different directions," Ross said, his head cloaked in a U.S. Navy ball cap. "We didn’t know what the hell we were running to or what."

When the dust settled, the explosion at the Navy base — about 14 miles from Concord, Calif. — had claimed 320 people. The two Navy ships were blown to shreds, the pier reduced to splinters. A nearby boxcar that had ferried munitions to the waterfront crumpled like a soda can.

In the nearby town of Port Chicago, the wall of the movie theater looked as if a giant had wheeled back a shoe and kicked in the side. The rumble was felt as far away as San Jose.

Ross ran until he fell in a ditch. Someone found him and took him to the hospital where he spent four days. The port was littered with debris and body parts — the result of what may be the world’s largest single blast before the atomic bomb.

The incident seemed to aim a spotlight into the segregated U.S. military — not just for the fact that poorly-trained African-Americans were relegated to its most dangerous jobs — but by what came after the explosion.

Wednesday marks the 75th anniversary of the Port Chicago disaster. A commemoration is set to take place to remember the lives lost in the deadly explosion. Pete Suratos reports.

A week after the tragedy, survivors of the blast were assembled by the officers and ordered to report to the nearby Mare Island Naval Shipyard in Vallejo to resume the task of loading munitions onto ships. When the sailors refused out of fear, fifty were charged with mutiny and faced a court-martial trial. All 50 men were African-American.

"When you look at it," said author Robert Allen who wrote a book called "The Port Chicago Mutiny," "the sheer injustice of these sailors being put on trial for mutiny and they had done nothing but stop in their tracks."

Ross was among the men who refused to work. But he was visited by a military chaplain who struck a bargain that if Ross would go to Mare Island and make ammunition, he could soon ship out aboard a military vessel. The deal helped Ross escape court-martial but not the terror of the work.

"My mother was crying," Ross recalled of his return to munitions loading, "24 hours a day."

Richard Soublet’s late father Maurice Soublet also survived the explosion, and like Ross opted to return to work loading ships.

"He felt he had an obligation to defend his country," Soublet said. "And he did what he thought was right."

The 50 men who had been courtmartialed were ultimately convicted of mutiny and sentenced to lengthy prison sentences of about 15 years. They were released early when the war ended. Allen said they came out to a military world that had changed since their imprisonment — one that was slowly embracing desegregation.

"The black sailors had no idea that their work stoppage at Port Chicago... had played a part in the desegregation of the Navy and then the other branches of the military," Allen said.

The 50 survivors who were court-martialed for mutiny have all since died. But that hasn’t stopped Allen and others from campaigning for their full pardon. Sailor Freddie Meeks was the only one who petitioned for a pardon while still alive which was granted by President Bill Clinton. But recent efforts to get the remaining men pardoned haven’t been successful. Even President Barack Obama failed to act on the request during his final time in office.

During a 1994 review of the case by the Navy, in which it declined to throw out the convictions, then Secretary of Defense William Perry said "Sailors are required to obey the orders of their superiors, even if those orders subject them to life-threatening danger."

Even though his father escaped court-martial, Soublet believes the mutiny conviction to be unjust.

"Here we are 75 years later," Soublet said. "And we still have’t found the compassion to pardon those other 49 people for what the government considered to be an injustice toward this country, when it was really an injustice toward those sailors."

Ross hasn’t stepped onto Port Chicago since the day of the explosion. He’s never seen the memorial that now stands at the shore of the Suisun Bay, where wooden pillars stand like sentries guarding the hallowed memories of the blast. Because the memorial, now run by the National Park Service, is still on an active Navy base, advanced reservations are required to visit. On July 17, the National Park Service will hold its annual memorial gathering at the site.

Ross has only recently felt the desire to visit the site again — to listen to the waves lapping at the pilings and to hear the wind whipping through the tall grass, a sense of peace to replace the horrific memories that still live in his mind, as vivid as the day they ignited.

"I was there," Ross said. "I was so happy to get away from there."