One buried the Temple of Zeus at Olympia under meters of debris, even though is was 15 km inland in 551 AD. (Science Daily News offers evidence.)
The Mt. Etna avalanche on Sicily 8,000 years ago dropped six cubic miles of rock into the sea and sent tsunamis reaching heights of 130 ft at landfall around the Mediterranean basin.
The immense Santorini volcano explosion ca. 1630 BC sent a great tsunami around the basin and may explain the origin of the Atlantis drowning legend.
The heartbreaking end of the Alexandrian library in Egypt is also attributed to a tsunami. (July 21 365 AD) Narratives highlight the public baths being fueled at one time by library parchment, but the truth involves more than one setback. We lost up to 700,000 scrolls. Scarcely one tenth of the ancients' documents and literature survives to our day.
Remember the slow motion horror?