Some handguns contain built-in safety devices intended to prevent injuries caused by erroneously believing that a handgun is loaded. A loaded chamber indicator indicates the presence of ammunition in the gun; a magazine safety prevents the gun from being fired when the ammunition magazine is removed, even if one round remains in the firing chamber. In our patent search these devices date back to the turn of the century. But on 1998 pistol models, only 11% contained a loaded chamber indicator and 14% had a magazine safety. In our random-digit-dial telephone survey of U.S. adults, 34.8% of poll respondents (incorrectly) thought that a firearm with its ammunition magazine removed could not be shot, or said that they did not know. Some of the 1100 unintentional gun deaths in the U.S. each year might be prevented if the prevalence of these and other safety devices is increased through legislation, litigation, or voluntary manufacturer action.