You must be thinking only wind. When you are 3 feet above sea level and the storm surge is 12 feet with a 12 to 18 feet wave on top of the storm surge, there is nothing left. This is where most of the damage is done. Millions of trees will be felled, too. The wind is strong enough to hurl objects into buildings and throw trucks into swimming pools.
A sobering thought: one gallon of water weighs around eight pounds; consider how many gallon jugs needed to stack to twelve feet high (about 16), then make that stack eight feet thick, to simulate a simple wave (8 x 16 = 128 jugs ... 128 x 8 = ! Just a single twelve foot wave can push a car away (3000 pound car x 1/4 has each wheel only carrying 750 pounds, so the wave has more weight (not even considering the inertia of the water moving or the buoyancy factor once the car is resting on water being pushed along like a battering ram) than each wheel is carrying. Folks, water when moving is very powerful. Storm surge plus wind whipped waves are a deadly force.