content: The scary thing is those canal walls gave them a lot more time to react compared to some of places that were hit. I think in some places the water came and went in around 3 minutes. Thankfully they have those flood warning sirens in a lot of places now, back when the 2004 tsunami happened in Indonesia and Sri Lanka I don't think they had any warning at all. that one killed over 200,000 people within a couple of minutes.