Everyone should know what to do in an emergency. Start training your kids when they can walk and talk. It does no good to scare them senseless: do not dwell on particulars.
I advocate the Giant Duck Emergency Preparedness System.
Why giant ducks? Why not? They have the distinct advantage of not currently being real. (They used to be real. If you have a budding paleontologist in your family, you could tell them about Bullockornis, the Demon Duck of Doom.) (Or not.)
In any situation, the same advice applies:
- Get out of danger.
- Get help.
- Help other people, as long as it does not put you back into danger.
This works for fires, floods, earthquakes, traffic accidents, bar fights, riots, medical emergencies, or people being mean to each other, among other situations.
Step one should be self-evident: get out of danger. Frequently this involves telling other people about the danger: "There is a fire in the kitchen!" can be shouted on your way out.
Step two is harder than it looks. You cannot just shout for help and expect people to respond appropriately. If you have a phone, call 911 (or 119, or 111, or whatever the local emergency services shortcut is). Be prepared to give them some details: What is happening, Where it is happening, Which services need to respond.
Step three can be scary, especially for people who are not used to having to function in an emergency. (In a well run society, that is most of us, most of the time.) Step three is to help other people -- and not to put ourselves back into danger. If you run back into a burning building to save someone, it is all too likely that the firefighters who arrive a minute later will need to save two people instead of one. Staying outside and being able to give firefighters needed information -- who is inside, where they are likely to be -- will be much more useful.