i) The overall homicide rate in Detroit rose from around ~7 per 100k in 1918 to a peak of 60 per 100k in 1991. That's nearly a 10X increase. That rise in crime was predominantly black on black and black on white. Naturally, the middle class whites who could afford it, fled the city. The book "Devil's Night" by Chafets gives some first hand documentation of the people who left, but I haven't read it. I have read "Carnasie" by Jonathan Rieder, who chronicles the exact same process in Brooklyn. Rieder's actually a liberal, but he's quite frank in his descriptions. Here a few excerpts:
Page 68: I met few residents who were strangers to street crime. If they had not been victimized, usually only one link in the chain of intimacy separated them from the victims...Most had a favorite story of horror. A trucker remembered defecating in his pants a few years earlier when five black youths cornered him in an elevator and placed a knifeblade against his throat. "They got two hundred dollars and a gold watch. They told me, 'Listen you white motherfucker, you ain't calling the law.' I ran and got in my car and set off the alarm. A group of blacks got around the car. If anybody made a move, I'd have run them over. The police came and we caught one of them. The judge gave them fucking to-year probation." The experience left an indelible imprint. He still relived the humiliation of soiling himself.
Page 69: One police officer explained that he earned his living by getting mugged. On his roving beat he had been mugged hundreds of times in five years. "I only been mugged by a white buy one time. All right, one instance, I went to the Brooklyn Navy Yard. They got a huge mugging rate there. I was dressed like an old man, a scar on my face, a little blood dripping like I was just anaccident, a cast on my arm, wearing old clothes." He had been out on the street for barely five or ten minutes when a band of black youths approached him. "First words I heard were, 'Get the old white man.' Somebody got around me, I got kicked, I got punched, one guy says, 'Grab him, let's take his wallet,' I got stabbed in the hand. It was a savage thing. I also found that it was because I was white. 'Look at the old white guy', 'Let's get the old white guy,' 'Get the fucking white scumbag.' What the hell does 'white' mean?"
Page 71: Many Canarsian's, concluding that vast stretches of Brooklyn had become dangerous places, nervously shifted their patterns of movement through the city or retreated into protective asylums...Whites ceded many areas of the city, but crime followed them into Canarsie. Social policy and administrative decisions, such as housing for the poor in middle income neighborhoods, school zoning and busing schemes, and inadaquate screening of public housing, increased the permeability of the community."
Page 73: After a flurry of muggings by black youths around the subway station near the low-income project, the residents were especially unnerved...One evening dozens of people crowded into a synagogue basement to discuss the muggins. The rabbi sermonized, "...Five blacks broke the ribs and shoulder bone of the last person who was attacked. The entire perimeter of the proejct has become hazardous...."
The statistics and the anectdotal evidence are overwhelming. Urban decay happened primarily because of violence committed by a subgroup of lower class black youths against whites. Once the middle class whites and blacks had fled those neighborhoods, the remaining lower class blacks did not have the cultural or economic capital to start businesses and create jobs, so the areas remained depressed.
This pattern of violence and decay happened all across America, from Boston to L.A.. But Detroit got it the worst and has basically never recovered. Why did Detroit get it the worst? A bunch of reasons: 1) Detroit had a higher perecentage of black residents. Detroit was 29% black in 1960, Chicago 22%, Boston only 9%. 2) Detroit went a lot further with its lax policing and urban housing projects, for liberals of the time it was considered a model city 3) style of urban renewal - as I understand it, Chicago restricted most of its housing projects to certain areas which resulted in only those areas getting blighted 4) chance of leadership - sometimes its just bad luck that one city gets a particularly destructive mayor 5) decline of the automative sector. I think this factor matters, but it's been overrated. The decline of Detroit itself went into high gear from 1965 to 1975. The automobile industry didn't really start to decline until the late 70's and 80's. Overall, Detroit metro gained population from 1960 through 2000. The real economic hardship to the region didn't hit until the 2008 crisis. That said, Detroit doesn't really have a strategic location, it was something of a one industry city, and it did not have any great universities, so the decline on that industry has meant the city has basically completely died, rather than limp along like Phildalphia 6) tipping point effects - all the small differences above can combine to pass a tipping point in which the city becomes completely unlivable.