By Catherine Jones

It’s been said that those who cannot learn from history are doomed to repeat it. And when it comes to the history of workplace safety—full of explosions, floods, fires and other disasters that left dozens or more maimed or dead—that’s a terrifying thought.

One of the most horrendous workplace tragedies in history took place 100 years ago this week, on March 25, 1911 in New York City at the Triangle Shirtwaist company’s factory.

Triangle was the quintessential sweatshop. Hundreds of workers were crowded together in appalling conditions when a fire broke out on the eighth floor. The fire spread quickly. With no fire protection system in the building and the only exit doors on each floor locked from the outside, the workers were trapped. Nearly 150 were killed.

Lawmakers and society learned from this event. The fire provoked outrage and led to major reforms, including the enactment of fire and building codes and the first workplace safety laws in the United States. It also sparked the creation of the American Society of Safety Engineers, a group of professionals who, for 100 years, have dedicated themselves to the health and safety of workers.