If Long Island, New York got hit by a Mega Tsunami generated from La Palma in the Cannery Islands. What would happen?
It wouldn't. La Palma is no bigger than Krakatoa, and while that tsunami did cross the Indian Ocean, by the time it did, it was about as high as a bad rip tide in high winds. Enough to kill people caught off guard, but not to do any lasting damage. And that island blew apart with explosive force rated VEI 7. Cumbre Vieja could suffer a massive landslide that would certainly generate a megatsunami locally, but landslide tsunamis CANNOT cross oceans the way megathrust tsunamis can. Their energy is too concentrated in one place, not spread out over a distance. By the time a La Palma tsunami made it across the Atlantic to New York, it wouldn't be terribly noticeable except to those who are watching for it.
Given that the highest elevation of Long Island is 400 feet, most of it would be scoured clean. Depends on the height of the tsunami, which we don't know. . .
No one would care
a lot of people could die cause of it
It's your scenario, whatever you think will happen.