A 2024 uprising in a San Francisco Sanctuary District, a turning point in Earth history that Sisko had to preserve after Gabriel Bell was killed.
The Bell Riots took place in 2024 in a Sanctuary District of San Francisco, a walled area where the unemployed and homeless were confined. The residents rose up, took hostages and seized the district, and the event became a turning point that pushed the United States toward ending the districts.
In the Deep Space Nine two-part story Past Tense, a transporter accident sends Sisko, Julian Bashir and Jadzia Dax back to 2024 shortly before the riots. Sisko and Bashir are placed in the Sanctuary District, where Gabriel Bell, the man history remembers as the leader of the uprising, is killed protecting them.
To save history, Sisko takes Bell's name and leads the riots in his place. He keeps the hostages alive and survives the final assault by government forces, and afterwards the historical records show Sisko's face as the picture of Gabriel Bell. History is restored, and the crew is retrieved by the Defiant.