Well, the answer to that depends on where there is a big earthquake. I went to a Tsunami preparedness seminar and learned a few things:
-The biggest impact on Los Angeles will be from a large earthquake in Alaska, Chile or Japan.
-L.A. will probably fare better than the California Central Coast.
-The first wave of a tsunami is usually NOT the largest.
-There is usually about 5 hours of warning between the time the earthquake hits and a tsunami getting here (if it’s in one of the places in the Pacific Rim–not in California).
-It can be 12 hours from the first tsunami wave until the highest wave.
-It is rare for the waves to go inland more than 1/2 mile.
-The biggest impact is going to be contaminated sediment or destruction near shore (ie. boat damage)
Here are some helpful websites:
Best advice: Find out if you live or work in a tsunami danger zone! Then find out if there is a tsunami evacuation route.