Eighty years later, the Port Chicago record changed.

Two explosions destroyed the ammunition-loading pier at Port Chicago Naval Magazine on 17 July 1944. They killed 320 sailors and civilians; 202 of the dead were Black enlisted sailors assigned to segregated loading units. The Navy's inquiry did not establish the initiating cause. Official accounts also vary slightly on the exact time and the number of people injured.

Unsafe labor conditions and inadequate training are essential to the history, but they do not prove which act or physical event ignited the ammunition. Preserving that distinction protects the record from a tempting shortcut: a well-documented unjust system does not make every specific causal claim about the blast knowable.

Surviving sailors were ordered back to ammunition work without an adequate explanation of the disaster or sufficient new training. Two hundred fifty-eight Black sailors refused. The Navy convicted 208 in summary courts-martial and prosecuted 50 together for mutiny. Thurgood Marshall and other critics challenged both the racial system and the fairness of the proceedings.

The refusal should not be collapsed into the unknown cause of the explosion. It arose after the blast, among people who had lost friends and coworkers and were being returned to dangerous labor inside a segregated institution. The prosecution created its own body of evidence about command, counsel, procedure, and unequal treatment.

In 2024, a Navy legal review found significant errors in the general and summary courts-martial, including improper mass trials and the denial of meaningful counsel. The Secretary of the Navy exonerated the remaining 256 defendants. That action did more than add a commemorative note: it changed the official legal status of the men and strengthened what the public record can say about the proceedings.

A careful archive now holds two different confidence levels at once. The ignition remains unresolved; the defective trials are officially acknowledged. Updating one conclusion does not require inventing certainty about the other. Port Chicago shows why a living historical record needs dated sources, visible revisions, and language capable of changing when institutions finally revisit their own evidence.