Water: you should have at least one gallon of water for a person to survive and so they wont dehydrate. Depending of how many people there are you should have at least one gallon of water per person.
Food: you should store at least food that will last for days even weeks and that wont go bad in about 1 day. Canned food would be the best option there is to survive.
Cloths: you should have some kind of extra cloths just in case you might get them dirty or might rip and some shoes in case the ones you have rip or something else happens
Blanket: to cover yourself in case its cold to sleep in or on depends on you situation they keep you warm if anything
tool: you need tools in case if somebody is trapped or in danger you need tools to protect yourself in case of an emergency or if you in a fight you can use that as a weapon
First Aid kit: in case if somebody is engered or need medical help you have a first aid kit to patch them up or if they need stitches you might have the supplys you need in order to help the person
Flahlight: you need a flash light in order to see at night and you might not have electricity and you gonna have to use a flahlight in order to see incase is something is going on or when you cant see whats going on cause you might be looking for something usefull
compass: to see where your at you might be able to tell with the starts but the compass you will be sure where your at and what direction you want to go to
lighter: you gonna need a lighter to make fire to cook or to even see in the night to make food even to make a big fire and use that as a signal or somthing usefull you might need it for
backpack: you need one on order to keep all you supplys in a safe place where you can easily get and carry everwhere in case you have to mive to a different place