to die is an excellent choice in that situation
well being that i'd rather live, i'd try and find high land... if not.. maybe go underground with scuba equipment, evade the force of the wave and just deal with the water? no scuba equipment? probly die lol
but when u say both east and west coast at the same time.. does it matter? only people immediately at the coastline (15miles at most) would be affected.... not even whole states would be obliterated.. just a lot of people dead