In the early 1960s, the Office of Civil Defense, in the United States Department of Defense, designated the basements and lower levels of thousands of buildings throughout the country, particularly public buildings, as radiation fallout shelters. These were shelters where citizens could evacuate to, in case of nuclear attack on the United States. Each shelter contained food rations (crackers), drinking water (in large metal drums), a Geiger Counter to measure radiation, and emergency medical supplies.

In theory, citizens could live in these shelters for a few weeks, to avoid most of the radiation fallout from the detonation of a nuclear bomb in the vicinity. Particularly during the Cuban Missile Crisis in October of 1962, school children were trained to "duck and cover" and to assemble in the school's fallout shelter, as children participate in school fire drills today.

This system for protecting the public from fallout radiation was never tested on a large scale and, fortunately, was never needed for an actual emergency. About ten to fifteen years after these radiation fallout shelters were conceived, it was determined that the cracker rations and water were no longer fit for human consumption. These supplies were never replaced; they were simply discarded. Other supplies were also, eventually, discarded. The metal drums (which included the Civil Defense logo), which held water, were often reused for other storage by the host building. In one instance, the Geiger Counter provided for the fallout shelter in the basement of the Shaler High School, in the northern Pittsburgh suburb of Glenshaw, was given to the high school science department.

The basement of the West End Branch of The Carnegie Library of Pittsburgh was designated as a radiation fallout shelter. As with all such designations, the Office of Civil Defense provided a yellow and black sign, with the Civil Defense logo, which was placed at the entrance to a building or other prominent location. After more than thirty years since the dissolution of the Office of Civil Defense, these historic relics of the "Cold War" are rapidly disappearing; only about a dozen or two such signs still exist in the Pittsburgh area (mostly on government and other public buildings). The sign on the West End Branch of The Carnegie Library of Pittsburgh was mounted just adjacent and east of the main entrance to the building.

With the dissolution of the Office of Civil Defense, this Civil Defense sign became the property of the legal owner of this Library building: the City of Pittsburgh. This sign continued to be mounted at this location until 2013, when it was removed during rehabilitation of the building.``