Bridges, Schmidt, and another Albion Hall militant won election to the local’s executive committee. In March 1934, as ILA locals all up and down the Pacific Coast moved toward a coastwise strike, the San Francisco local elected a large strike committee that then elected Bridges as chair. On May 9 ten thousand to fifteen thousand longshoremen walked out from northern Washington to Southern California, demanding a coastwise contract, union hiring halls, a six-hour day, and better wages, demands established by the ILA district leaders in July 1933. Greeted by picket lines upon entering Pacific Coast ports, ships’ crews and officers quickly went on strike with issues of their own, adding more than six thousand seamen, marine firemen, marine cooks and stewards, marine engineers, and masters, mates, and pilots to the number on strike. Most teamsters refused to move cargoes unloaded by strikebreakers. Bridges, chairman of the strike committee for the largest ILA local, rapidly emerged as de facto leader of the local and, increasingly, for the entire coastwise strike.

The Young Communist League called a meeting on the waterfront for noon, Memorial Day, May 30, to demonstrate against war and fascism and support the strikers. The YCL distributed leaflets widely, but the police refused a permit for the demonstration. Party officials tried to call off the meeting, but 250–300 young people gathered, milling in confusion when no speakers appeared. One version of events was that a YCL leader was hoisted to another’s shoulders to explain that the meeting had been canceled. When he spoke, police attacked the crowd with nightsticks and blackjacks. The police version was that they were pelted with rocks before they attacked the crowd. A committee representing twenty-two organizations, headed by a Presbyterian minister, interviewed witnesses before calling it a “riot planned in advance by the police,” one of the first usages of the concept of a police riot.