Suicide

Related:
* Suicide bombers - if the purpose is to sacrifice oneself to kill many.

Note: This is a spoiler if this happens according to the main story and not by some game mechanic.

Possible gameplay mishaps like shooting a rocket at a nearby wall, blowing a grenade in your hand, jumping off a cliff into endless pit and similar player's mistakes or intentional actions should not be considered. Purely plot based or a gameplay mechanic.

This should not be considered for games which offer a "suicide" console command which is usually intended for desperate players in multiplayer games who get stuck and can't get out by any other means, this command often works in singleplayer mode as well for no real purpose.