It turns out that storm tides were largely responsible for the 6,000-12,000 deaths in the Galveston Storm of 1900 (the deadliest natural disaster in the United States, even now). Those tides were 8 to 15 feet.

Since then the elevation of the city has been raised, but with a storm surge up to 22 feet above sea level expected, it is foolhardy to remain on the island, as up to 40% of Galveston’s population has reportedly done.