Monorail train wreckage
Three or more raiders have set camp next to four crashed monorail train cars. The camp is made of scrap metal planks on the floor, 2 shopping carts, a fire pit and a bathtub.
Duck and Cover! - on the floor next to the bathtub.
In the Fallout 3 Official Game Guide, it states that the camp is "northwest" of Germantown Police HQ, when it is actually northeast.
Monorail train wreckage appears only in Fallout 3.