Its not the height of the wave thats deadly, its the amount of water thats behind it caused by billions of tons of displaced water. The Tsunami of boxing day a few years ago that killed around a third of a million people was only around 8 feet high in places. 8 feet high 'wind' generated waves are different from 8 feet Tsunami generated waves by a long shot, with the later having billions of tons of momentum behind it.
If you want to talk about height, feast your eyes on this for a largest Tsunami ever witnessed.
Extreme Science
Thats 500m in height in case you can't be bothered to read it all. This one was generated by half a hillside collapsing into the sea and only affected a short area because the water displaced was only in the bay where the landslip occured. 😯