A 3' wave is no big deal....unless its 15 miles deep and continues flowing onshore for 2 hours. The height of the wave is less important than the duration and the volume of water behind it.
I live an hour from the beach in northern Oregon. There was no appreciable damage up here, but the town of Brookings down on the California border got creamed, with several million $$ worth of damage to the port.
As far as I am concerned, anybody who disregards a tsunami warning and goes out onto the beach needs to spend a week in jail. When idiots like that get in trouble, the Coast Guard has to go out there in a lifeboat or a helicopter to save them. I could care less whether some idiot dies, but I dont like the fact that Coast Guard and other emergency personnel have to risk their own lives attempting a rescue.