Every school and daycare in the province is required by law to have emergency plans for a variety of events.  They must also have regular drills so the staff and the children understand the procedures.  Most children appear to take these preparations in stride, but for others, thinking about the bad things that could happen here can be a source of stress and anxiety.  Children comprehend the world through their own experiences.  They learn quickly what to expect from a birthday party, a trip to the dentist or the first day of school.  Helping them to develop realistic expectations of an emergency event will help them cope with both the practice drills and the real thing.
A good place to start may be ensuring your children are aware of, and understand the family's emergency plan.  There are a few scenarios, depending on where you live, when evacuation may be necessary.  If you live in the tsunami inundation zone, make sure the kids know the physical location you will be evacuating to.  This is one the reasons it's important that people plan to go to the home of family or friends when evacuation is required.  Children (and adults!) will already be familiar with the people and the environment, and will settle easier.  It will be much more difficult for kids to imagine sleeping in the place they usually go to roller skate or to a birthday party than at a relative's house.
Talk about what will happen if the family is separated when an event occurs.  Parents may be at work, kids at school, or another acitivity.  The kids should know that they may be at school or daycare for a while until parents can pick them up.  If this is the expectation ahead of time, children won't be concerned when it happens.  If you are not familiar with the emergency plan of your child's school or daycare, ask them.  As well as ensuring your peace of mind, you can discuss the details with your children so they understand they will be safe and cared for if they are away from you. 
Involve the entire family in the development of your emergency supplies.  Talk about what kind of food is appropriate and then let the kids choose some of the items.  Let them choose a book or a game (that doesn't need batteries) to put in it.  It might take a little bit longer with the kids "help" but it's an excellent opportunity to answer their questions and allay their fears.  Surviving a disaster will be a very stressful time for all of us, and having food your kids like to eat and something for them to do will keep them busy while you manage the big stuff.
Discuss what may happen locally in an emergency. The pictures of completely collapsed concrete buildings after an earthquake in Haiti or the Middle East are not realistic expectations of a similar event here because of the differences in building codes and materials.  Children can understand how wood frame construction is much more resilient in an earthquake.  Participate in the ShakeOut drill in October this year to reinforce how to "Drop, Cover and Hold On".  If  pictures of the tsunamis in other parts of the world are causing anxiety, explain how our tsunami warning system works and talk about the evacuation route you will take.  If you live in the inundation zone, let the kids listen and ask questions when the Port Alberni firefighters knock on your door as part of the awareness campaign conducted early every summer.  Sometimes hearing a message from a trusted source like a firefighter or police officer is more reassuring.
Children understand a lot more than we give them credit for sometimes.  They have vivid imaginations and without concrete answers to their questions it's easy for those imaginations to go in unnecessary and scary directions.  Talking about disasters in the safe and secure environment of home will help all members of your family survive an emergency event with less trauma for everyone.