Pachyderms Protect People

Elephants saved tourists from tsunami. Very cool.

It's always cool to see that large animals, which are chained and trained, will go to great lengths to protect human life. But the question is - how did they know? Was it the low rumble that they picked up through the ground?

Perhaps this is a good thing to find out - it could be something which we could emulate with machines, as far as the sensing. Directly linked to alarms, this could be a powerful and reasonable means of last minute alarm.