San Francisco progressives have spent decades in a multi-front battle against gentrification. The struggle to prevent the displacement of low-income working people from the city has led to rent controls and eviction protections, zoning restrictions, highrise limitations, inclusionary housing, and a constant push for truly affordable housing. But stopping gentrification alone does not make low-income neighborhoods desirable, or even livable. In San Francisco, neighborhoods that have defeated gentrification have been treated as "containment zones," meaning that unreasonable levels of crime, violence and drugs are tolerated so that such activities do not spread to upscale areas. The Tenderloin has long been one of the city's leading containment zones, but those days are over. A large contingent of residents, workers and merchants will be delivering this message to city officials today, in a March for Safety that heralds a new chapter in the Tenderloin's---and San Francisco's---history.