I remember a story about about the Labor Day hurricane that struck Florida in 1935. It was a category 5 storm.
The 1928 Okeechobee hurricane got its name from what its did to Lake Okeechobee. The winds caused a twenty foot storm surge on the lake, pushing water well inland from the lake. This storm killed over 4000 people in the state.
Hurricane Donna, in 1960, was only a category 3 storm when it hit Florida's west coast. Tampa, St. Petersburg, and Fort Myers had half the population they do today. The storm surge shattered seawalls and swamped the cities.