Ninety percent of the people killed by the tidal waves could have survived if they knew to run when the sea receded. It's not high tech and doesn't even require an expensive early warning system.
Just a bit of knowledge and a clear path to high ground.
Well said.
Well, it's not a big deal to me either way, but anyone who focused on the region could've easily predicted that "other parts within the section of this fault should be considered dangerous over the next few decades." Indonesia has been notable for seismic activity since a very long time ago and it's not much of a stretch to expect a major quake in this vicinity.
As for warning of tsunami, there was a very devastating earthquake-induced tsunami just a few years ago in Papua New Guinea (aside from just the general well-known risk of tsunami). The alarm over the potential for another disaster had been raised by that, but people still remained complacent.
Now, they're not.