On March 25, 1911, the Triangle Shirtwaist Factory caught fire. The stairwells and exits were locked to discourage employee theft, trapping many inside. 146 workers, 123 women and 23 men, were killed.
The accident helped spur legislation to improve factory safety. It also led to the growth of the International Ladies' Garment Workers' Union (ILGWU), which fought for better working conditions.