Walter (Fallout 3)

Walter, is a citizen of Megaton city and runs the Water Processing Plant. He is an old, white-haired man in a mechanic suit.

Tasks
He gives you a minor quest to fix broken pipes around Megaton when you ask "What needs to be done around here?". Once finished with that he would then like you to bring him any Scrap Metal the Player Character finds along his/her journey. He will give you 10 caps per piece, or positive Karma and XP if you refuse to take the caps. This is an effective way to fly through the lower levels.

Appearances
Walter appears only in Fallout 3.

Bugs
Walter is one of the named Megaton residents who may mysteriously die or disappear when the player is not in the town. It has been reported that his "disappearance" seems to coincide with the character's introduction to the Outcast Casdin on the PS3 version of the game, who also happens to accept scrap metal. However, on the PC version, Walter has been found dead without meeting Casdin, upon returning to town for the first time after completing Walter's minor quest. It appears more likely to be a pathing issue that eventually causes Walter to fall to his death and be found dead at the bottom of a slope to the left of the clinic. On the PC version you can recover him by using console commands described in this guide.

The disappearance of Walter can also happen on the Xbox 360 version with some reports of him not even appearing at any point of the game.

EDIT: It seems that for some reason Walter will wander around in the airplane structure on the roof of Lucas Simms' house, which is accessible through a trap door in the ceiling. He probably falls from this area while attempting to return to the water processing plant meeting his demise on the pipes below.