People are the most destructive force in a shtf disaster. Of course, the seriously cataclysmic disasters will cause tons of damage but the true threat to those who make it are the people around them. More importantly we are talking about the people who are unprepared. They pose the biggest threat because they are desperate. This is a great article that looks at dealing with unreasonable people from the perspective of those who have dealt with them in real life situations.
Dealing with the masses will be a big part of surviving a collapse. Not only will you have to deal with these people you may even need their help. You may need to ask them for things or at the very least you will have to barter for things. Doesn’t sound like fun but its a skill set you will need.