So, I was browsing the game direcotry looking for assets and stuff like that and I found in DL1 this file:
DEADLOCK.DPE
From the internet:

"The DPE file type is primarily associated with 'Swimming Pools & Tanks (DPwinEHE. Piscinas y Depósitos)' by Procedimientos-Uno, SL. DPwinEHE is a CAD/CAE product for the structural design of reinforced concrete swimming pools and water tanks."

Strange......or not?