The Divide (2011)

Trailer: 

The Divide (2011) is a psychological thriller set in the aftermath of a nuclear attack. A group of survivors finds refuge in the basement of their apartment building, but as they confront their new reality, tensions rise and human nature is put to the test.

Isolated from the outside world, they grapple with fear, paranoia, and desperation, leading to conflicts that threaten to tear them apart.

As supplies dwindle and their mental states deteriorate, the group is forced to confront their darkest instincts, resulting in a harrowing struggle for survival. The film explores themes of humanity, morality, and the breakdown of social order in extreme circumstances.