A fire of incendiary origin occurred at the Ozark Hotel in Seattle, Washington, on March 20, 1970 and
claimed the lives of 20 occupants. Fire investigators determined that a flammable liquid had been poured and ignited on the first-floor level of two open stairways. The fire quickly spread throughout the building rendering the stairways and corridors useless. As a result, 20 occupants perished, either from smoke inhalation or from injuries suffered when jumped from the upper stories.
NFPA members can download the Fire Journal article January 1971 Fire Journal article Those interested in more information about hotel and motel fires can download NFPA's Hotel and Motel Structure Fires report and fact sheet More information on intentional fires NFPA's report on Intentional Fires
One of the stairways in the Ozark Hotel. Seattle Times