The deadly Iroquois Theatre fire of 1903 prompted numerous fire safety reforms still in place today, as described in an upcoming episode of WTTW-TV’s “Chicago Stories” series that explores downtown Chicago disasters with lasting impact. Its horrible toll also helped inspire the creation of UL labels, a symbol of safety now widely recognized by consumers. Formed in 1906, the UL Label Service was in part a response to findings that the Iroquois Theatre’s six fire extinguishers and other so-called fire protection measures were ineffective.