A small point first - I think island should be capitalised: Island.
Two things sound unnatural to me. First, a tsunami does not "attack", it "hits".
Secondly, the tsunami occurred in 2004, which for most people is not a long time ago, although it possibly could be in some contexts.
Phuket Island in Thailand was hit a tsunami in 2004. Even excellent swimmers couldn't survive.
Student or Learner