Here is a low poly game asset I made to practice my workflow to get something into a game engine. I made some variations so it could easily be repeated throughout a scene, but have a few a player could interact with for cover or hide from enemies.
You can purchase the models and textures and view more renders at: http://www.turbosquid.com/3d-models/3ds-max-20ft-cargo-container/967022
Now on the Unity asset store!: https://www.assetstore.unity3d.com/en/#!/content/48000