Rucksack in the bus

 is a Phantom Stash/Bugged Stash featured in S.T.A.L.K.E.R.: Lost Alpha.

"They chased us down and we held out in the bus. Ganta didn't make it. His stuff is still there."

- PDA description

Overview

 * The stash coordinates cannot be acquired in v1.4005 before due to the lack of Duty and Loner corpses on the level.
 * In v1.4007 the stash definition was removed from the gamefiles, though the story ID and the PDA texts as well as the rucksack itself still exist.