Killed in action (KIA) is a casualty classification generally used by militaries to describe the deaths of their own combatants at the hands of hostile forces. The United States Department of Defense, for example, says that those declared KIA did not need to have fired their weapons, but only to have been killed due to hostile attack. KIAs include those killed by friendly fire in the midst of combat, but not from incidents such as accidental vehicle crashes, murder or other non-hostile events or terrorism. KIA can be applied both to front-line combat troops and to naval, air and support troops. Someone who is killed in action during a particular event is denoted with a † (dagger) beside their name to signify their death in that event or events.