Neb. Rev. Stat. § 48-420: Fire escapes; when required.

Every factory or other institution, more than two stories in height, shall be equipped with outside fireproof iron stairways, chutes or toboggans, and one automatic fire escape for every fifteen persons working or congregating therein at any time, who, for any reason, are unable to reach or use the outside fireproof stairways, chutes or toboggans.