Dianne Odell, 61, had been confined to the iron lung a 7-foot metal tube since she was stricken by polio at age 3.
Family members were unable to get an emergency generator working after a power failure knocked out electricity to the Odell family's residence near Jackson, northeast of Memphis, brother-in-law Will Beyer said.
"We did everything we could do but we couldn't keep her breathing," Beyer said.
"Dianne had gotten a lot weaker over the past several months and she just didn't have the strength to keep going.''
The Madison County Sheriff's office said emergency crews could do little to help. The local power company reported spotty power outages in the area because of a tree that fell on a power line.
Despite deformity from bulbo-spinal polio that stopped her from using a portable machine, Odell earned a high school diploma and wrote a children's book.