Do hurricanes really raise the price of gas or is it just price gouging?

Do hurricanes really raise the price of gasoline or is it just a reason for price gouging? I believe that it is a reason to simply raise prices and take advantage of a natural disaster. When the gas companies see a natural disaster coming and they have scared Americans they know that they can jack up prices and take advantage of everyone. The hurricanes hardly affected any oil refineries at all. Therefore the gas prices should not have hiked like they did. I think it is interesting that after Katrina the prices went up, but after Rita the prices stayed the same. The gas hikes are because of the greed of the oil companies and nothing else.