Triangle: The Fire That Changed America, by David von Dreihle is a tremendous source of informationm on the fire and a wonderfully written book to boot.
American Experience: The Triangle Fire is an excellent episode of the PBS documentary series about the fire.
Remembering the 1911 Triangle Factory Fire is a great resource which includes about lots of recorded and written interviews with survivors years later, a list of victims and witnesses, a model of the ninth floor, and tons of other information.
In this video, former NY senator Serphin Maltese speaks of his grandmother and two aunts who all died in the fire and how the fire impacted both his own family and workplace safety in the years following.
This clip from “The Story of Us” portrays the Triangle Shirtwaist Fire.