Negligence?

Say two workers are working around lethal gas and one workers mask fails. The other worker wearing the mask tries to save the other but dies in the process of trying to save. Two other perbyers not wearing masks try to save them but also die. THe wife of a perbyer sues the mask company and wins. This was because of the "danger invites rescue" doctrine correct? Any other ysis information? was there any other doctrine involved? Was it the mask companies fault for the death of the perbyers?