As the title says what you you do in case of a mass Zombie outbreak? Run? Hide? Fight? Here's what I'll do. I'll turn my home area into a Safe heaven. Thanks to it being a block of flats and the way it's built it's basically got flats in a half circle. First I'll get all my friends and family members together, together we stand a better chance of survival. Then I'll start acquiring buss's and Lorries, Long vehicles so I can use them as walls and place them around my area to keep the zombies out. Arm my self with weapons of course, find a gun retail and obtain guns any means possible. Food! Gather all food and water from Super Markets before other people think the same idea and also in my area turn it into a farm with animals and crops to keep the food supply going and then once my base is set! Attack and kill all Zombies!