What event in 1911 focused attention on the need to protect factory workers?

The huge disaster that happened in the Triangle shirtwaist factory.

               Why was this event important?

Basically, the factory didn't posses enough exit doors to escape from the fire.
The fire extinguisher wasn't enough.
No fire signal.

        That should definitely teach the government a lesson that they should protect factory workers.

     The triangle shirtwaist fire was the most horrific disaster apart from 9/11

The answer is c. hope that