Photo: GenDisasters.comOn Dec. 20, 1970, an arson fire raced through Pioneer International Hotel in Tuscon, Arizona, claiming 29 lives - including the hotel owner and his wife in their penthouse apartment. Built 1929, the hotel had open stairways. The Associated Press reported hotel guests ``smelled a volatile substance in the corridors.'' Thirty-three firefighters were injured, according to the Tuscon Citizen.
