Humans today were not alive during past global cataclysms, so they have no ‘memory’ of such events. As a consequence, most humans believe that these types of things cannot happen, because in their memory, nothing like that has ever happened. So there is no reason to prepare for such an event. Very few people would believe that a tsunami 3 miles high is possible. Normally, this type of wave is impossible, but it can and does happen when a meteor strikes an ocean, which then creates a huge wave, that can be up to 3 miles tall.
via Scientific Data And Evidence, Detailing History Of 5 Comet Or Huge Meteor Storm Strikes On Earth, Which Created Planetary Upheaval And/Or Extinction Events; Is Human Civilization Ready For The Next Cosmic Or Natural Disaster? | A Green Road Journal