I have emergency supplies in case of earthquakes.
Minimum of 3 days' worth of food and water per person, at home and at the office. I actually have more than a 3-day supply at home. First aid kits, at home and in the car. A flash light and hard hat near my bed, plus a pair of shoes (you don't want to step on any broken glass shards in bare feet).
The food and water get rotated on a regular basis, but I am not too concerned about expiration dates. I stock up at regular intervals (every 3 months or so).
I try to keep a 3-6 month supply of non-food items on hand: soap, toothpaste, shampoo, papertowels, toilet paper, laundry and dish detergents, etc.
Chlorine bleach to sanitize the water for drinking.
A way to cook without using gas or electricity (charcoal, barbecue grill)
Trash bags for waste disposal (one is not supposed to flush human waste if there's any damage to the sewer system; one is to line the toilet with a trash bag and bury the waste). A spade to dig to bury the waste. I also kept the portable toilet given for my mother's use after her hip replacement surgery - if the house is damaged and I can't use the indoor toilet, I can use the portable one.
Since I am on prescription medications, I try to keep at least a 2 weeks' supply of medications on hand.
The gas tank is usually kept at least half full.
And, I keep a certain amount of cash, on hand, in case of an emergency - if electricity is out, credit cards, ATM machines, etc. will be out of service.