I was watching Nightline last night - apparently the US seismologists called the seismologists where it happened 15 minutes after it happened and it didn't hit land until 2 hours later with some places not getting it for 6 hours. Plenty of time to save thousands
As far as the US helping, as Michael said, we have always been there. I've not seen anyone help us with hurricanes, wildfires, WTC (financial help) but we are always there for others. And we're the bad guys.