Cleveland Clinic fire of 1929

A major structure fire occurred at the Cleveland Clinic in Cleveland, Ohio, United States, on May 15, 1929. Nitrocellulose X-ray film ignited in a basement storage room, emitting a poisonous yellowish-brown gas which spread throughout much of the Clinic and subsequently exploded several times.

Source: Wikipedia — Cleveland Clinic fire of 1929 (CC BY-SA 4.0)