Behind you is an open vent. You had heard Subject Zero used those to travel in, but as he is no longer around they should be safe for you to use. You crawl further into the vent and hear the wall to the storage crack. Behemoth smashes everything in the storage but then there is silence. When you start to think he is gone, he charges at the vent and tries to climb through it. Even though he is too big to fit, he forces himself to fit as he uses his brute strength to tear the vent open in order to follow you.