Paul Levy reports that one of his neighbors still has a fallout shelter installed by a previous owner:

... The cover of this bomb shelter is made out of lead to protect you from radioactivity -- since the government would promptly announce through the CONELRAD alert system that intercontinental ballistic missiles were en route so you would have enough time to get into the shelter. A nearby vent shaft brings in outside air -- no doubt through a filter that was sold as incredibly effective in sifting out any contaminants. Electricity was provided by, ahem, a line from your house -- as though the supply would stay remarkably reliable through the bombardment of the Boston metropolitan area. ...