Originally Posted by Guy Who Rages
Well the Rat Man frequently talks about hell, and Randall says he's in hell a few times throughout the game. I don't take it's supposed to be taken literally, but maybe all the serial killers indicate that this is a "wrath of god" type of apocalypse.
re-read his diary. pay particularly close attention to pages 17-18 & 29-30. trust me when I say they're connected.