As economist's point out.
1) There is a severe shortage of some product: gasoline in this instance
2) Retailers do not raise the price, everyone with a vehicle rushes to the gas station, whether they need gas or not.
3) Gas stations run out of fuel leaving large numbers of people sitting in line. This includes people whose tanks were near empty and who won't be able to get to school/work/whatever else.
One the other hand we had situation B: retailers double the price of fuel. Then only the people who must have fuel go and buy it. Yes it costs them more but they can operate their vehicles. Furthermore gas distributors have a big incentive to rush more fuel to the stations, more so than if the prices were not raised.
Now the problem with this is that socialists HATE the idea of someone making a buck. And so will demand 'antiprofiteering laws', yes antiprofit is the ideal description of socialism.