Thousands of workers, union members and activists are expected to flood downtown Los Angeles on Friday for May Day , with organizers urging supports to skip work, school and shopping as part of a broader “economic blackout.” The main rally is scheduled to begin at 10 a.m. at MacArthur Park , followed by a march to Grand Park after a speaking program. Labor and immigrant rights groups say the demonstrations are part of International Workers’ Day, with similar events planned across California