Shortly before 5:00 p.m. on December 20, 1965, a fire of suspicious origin started in the balcony of the auditorium in the second and third stories of the Jewish Community Center in Yonkers, New York. The evidence suggests that someone, using a flammable liquid as an accelerant, set a fire at one end of the balcony, beside the stage. Within a few minutes, the fire had spread to involve large plastic panels and other combustibles in the balcony. Some occupants of the upper floors of the building took refuge in various rooms in the building or on outdoor balconies. One of these rooms had its door open, and all 12 people in this room were killed.
NFPA members can read a Fire Journal article from May 1966.