Today, the water main down the street really blew, flooding everywhere. This is a perfect time to review our earthquake procedures.
Any city has hundreds of spots where the water mains are on the verge of busting. An earthquake will make these all go at once. Expect no water for 3 days. By the third day we should have trucked-in water, but some areas may be out for a week.
A good planning scenario is the 1 in 500 earthquake, which is the type that has devastated many a city. For a city such as Los Angeles this is an M8, and for Toronto, and most of the Eastern Seaboard, this is a near-field M6. Nuclear plants should plan for an M7 on a megathrust.
Our (Toronto) M6 should blow out the electricity grid, and shut down all the nuclear stations. They aren't prepared and it'll surprise the hell out of them. I really have to think a lot of gas lines will rupture.
So, today our main lesson is tap water, of which I have none right now. Immediately turn off the hot water tank, you'll need that water. Everybody will instinctively flush the toilets anyway, so tape the handles. If it's yellow, let it mellow. You should always have 3 days of drinking water. I use a water cooler/heater, so I always keep a spare jug or two. If anything starts to rumble, get another one!
Once the hot water tank cools you can tap it for flush water (or drinking water if you didn't listen to the above). Crack open both the kitchen taps. This will also tell you when the water is back on (and vents the lines so you can drain the hot water tank). Expect the first water to be dirty. To tap the hot water tank, you need a medium bucket, and a slot-head screw driver. You should do this regularly anyway, since the first water is black as pitch.
I think the gas will be back before the electricity (a black start is difficult), so I have a mechanical gas fireplace for heat. A winter earthquake will be horrible.