A Statistical Analysis of Bell System Building Fires, 1971-1977

Fires occurring in Bell System operating company or Long Lines telephone buildings or adjacent grounds, but not fires in Western Electric plants, are reported to AT&T on a standard form entitled "American Telephone and Telegraph Company Fire Report--Buildings" (Form E-5000), issued in 1962 and revised in 1969 and 1976. This paper analyzes approximately 1500 of these reports, covering fires that occurred in the years 1971 through 1977. Although Bell System summary statistics on fires go back a decade or more, few reports on fires prior to 1971 are, apparently, now available. The issuance of a fire report is governed by the following definition of a fire: 2769 Any occurrence that produces heat or flame and smoke in telephone company property or leased space, that affects service, causes property or equipment damage, and/or endangers inhabitants. For the purpose of this paper, this has been interpreted to mean that a fire is characterized by an open flame, arcing, or sparks, visible smoke, or a combination of these; if the fire is out before it is detected, the site is marked by ashes, charred areas, or discoloration. Furthermore, an explosion is counted as a fire. However, a burning odor unaccompanied by smoke that cannot be traced to evidence of the above nature is not counted as a fire. All fires on company-occupied premises, either owned or leased, are supposed to be reported. Specifically, in this paper a fire is included if (i) it begins on non-Bell property and spreads to Bell property, damaging it (including water damage by fire fighters) or (ii) it occurs in a vehicle parked on Bell premises.