The inner city mob myth

I remember noticing, at the beginning of the horror last Tuesday, that the US media were obsessed with looting. The reporters on the ground were trying to talk about a broad range of evacuation problems, while the anchors sitting in their New York studios kept focusing on looting -- how's the looting, any signs of looting, where are the looters, did you get any video of looting...on and on and on.
I remember noticing, at the height of the horror last Thursday, that it was very odd and tragic that people didn't just walk out of New Orleans by themselves. I thought maybe some had but there were just too many old people and babies left to make it.
Now both the things have turned out to be part of the same story -- the inner city mob myth. An inordinate and excessive fear of looters caused good-ole-boy police in the suburban neighbourhoods surrounding New Orleans to set up barricades which prevented the poor people of New Orleans from walking out to safety. Kevin Drum posts "Savagery...a followup..." which covers some of the details.
Its all part of this "inner city mob" myth in American culture -- the apparently primal fear of suburbia that a mob of rampaging, looting, screaming, tire-iron-clutching black people are going to come running down their street -- breakin' windows and rapin' women and crushin' the flowerbeds and tailored lawns.
Disaster planning in the US doesn't seem to have acknowledged the power of this myth. It may well have been a major factor in the disaster that was New Orleans, and certainly would be a factor in many many other US cities -- where the central areas of the city are populated primarily by poor black people while wealthier white people live in the surrounding suburbs and have white police forces who know their job is to protect suburbia from the black mobs. So in American cities, if something disasterous happens which creates refugees in the city core, the disaster will be compounded because the suburbs will be too afraid to let their neighbours in.
And I call it a myth because it is -- I am no expert on American history but when was there ever an example of an inner city mob which rampaged around the suburbs? I can't think of one. All the mobs I remember seeing on TV -- Detroit, Watts, the Rodney King riots, etc -- actually destroyed just their own neighbourhoods, not anyone else's.
In New Orleans, there were no mobs at all. Just desperate, suffering people.
The Wikipedia article on inner cities points out that in other areas of the world like London and Paris it is the wealthier and higher-class people who live downtown. But even in Canadian cities, which follow the American model where poor people live in downtown neighbourhoods, there is not this same kind of dynamic at all. In Canada, we have escaped this particular myth and thus this type of fear -- maybe this is why we also have escaped the American gun culture as well.