The Third Ministerial Conference of the World Trade Organization (WTO) was held in Seattle from November 30 to December 3, 1999. Trade ministers and other officials from the WTO's 135 member nations met in an unsuccessful attempt to plan negotiations to further deregulate free trade. Tens of thousands of activists for many causes gathered to protest what they saw as the WTO's favoring of corporate interests over social and environmental concerns.

By 10am on November 30, police were ordered to clear blocked intersections near the Convention Center. The heavy police response, which continued into the evening, included the use of concussion grenades, tear gas, pepper spray, and rubber bullets. Here, on Third Avenue near Stewart Street, a protester removes his gas mask after a rubber bullet had shattered the eyepiece and injured him.