Recognize warnings signs (both natural and official)

When you feel a strong or long coastal earthquake, be aware that a tsunami may have been generated that will arrive in minutes. Evacuate immediately inland to higher ground. Do not wait for official evacuation orders.

When there a distant tsunami that is generated far away, stay alert to your national tsunami warning center and local officials. Tsunami Warning Centers will issue a Tsunami Warning when scientists are certain that a real tsunami threat exists. Be ready to evacuate by preparing you Disaster Supplies Kit, locating family members, reviewing evacuation routes, and if time permits, securing unanchored objects around your home or business. Emergency Management or Civil Defense officials will issue evacuation orders advising the public when to evacuate tsunami hazard zones. Follow their instructions.

Tsunami Warning Centers will cancel a Tsunami Warning when destructive waves stop arriving to the coast, but that does not mean it is safe for the public to re-enter since buildings may be unsafe and downed live power lines are dangerous. Return home only after local officials tell you it is safe. A tsunami is a series of waves that may continue for many hours. Do not assume that after one wave the danger is over. The next wave may be larger than the first one.

For more preparedness information, visit http://www.redcross.org/get-help/how-to-prepare-for-emergencies

Additional useful information can be found on the US 'During a Tsunami' site
https://www.weather.gov/safety/tsunami-during