Imagine for a moment that every single person living in the city of San Jose, Calif., plus an additional 150,000 or so, just up and left. Vanished. Poof. Gone. Leaving their homes, business buildings and factories behind.

That is, in effect, what has happened to the city of Detroit, according to 2010 U.S. Census data. The city that boasted 1.8 million residents in 1950, and was the nation’s economic engine for most of the 20th century, now is home to 714,000 people, a population loss of 1.1 million ― with a 25 percent drop in the last decade alone.

It’s an unprecedented collapse of a major American city. It’s not as if the population was dropping nationwide; it’s going up. Just not in Detroit. Its closest “outmigration” rival is Chicago, a five-hour drive to the west, which has lost about 964,000 people since 1950 but still holds about 2.7 million people, down 25 percent from its peak of 3.62 million in 1950.

In Detroit, the loss amounts to a staggering 60 percent of the city’s peak population. It is now smaller than Charlotte, North Carolina, and Fort Worth. More people have left Detroit than live in San Francisco; more people have left in the last decade than live in St. Petersburg, Florida.

There are all sorts of implications here, both for Detroit and for the nation. The 2010 census counts for Detroit (and Chicago) were much lower than local officials, and earlier census estimates, had predicted. That raises the question of whether there were problems with the count last year or in 2000, setting false benchmarks. Detroit officials say they plan to challenge the numbers, and Mayor David Bing announced he wants to find 40,000 Detroiters who were missed to try to push the count above the 750,000 mark, a key threshold for formulas used in distributing federal urban aid.

But there are two larger issues that have broader national implications. The first is, when we look at Detroit, are we confronted with the remnants of the nation’s industrial past or a harbinger of its urban future?

The second is, what are we going to do about it? And no, that’s not Detroit’s problem alone. If a similar collapse happened to San Francisco or San Diego or Denver or Dallas, there would be national cries for intervention. Detroit we treat like a crash on the freeway: something to gawk at, then forget while we blame auto executives ― the driver ― for their follies and ignore the injured passengers.

Detroit has played a significant role in my life. I worked there for a decade, nearly a third of my career as a journalist. My two sons were born there. I endured 18 months on a picket line during the newspaper strike that began in July 1995. And I keep getting drawn back. I was there most recently in January for three weeks researching a book I’m writing on the history of Detroit, trying to explain to outsiders how it got to be in the mess it’s in.

The collapse of Detroit has roots in intentional de-industrialization by the Big Three automakers, which in the 1950s began aggressively spider-webbing operations across the nation to produce cars closer to regional markets, and to reduce labor costs by investing in less labor-friendly places than union-heavy Detroit. Their flight was augmented by government policies that, in the 1970s and 1980s particularly, forced municipalities and states to compete with each other for jobs by offering corporate tax breaks and other inducements to keep or draw business investments, a bit of whipsawing that helped companies profit at the expense of communities.

Racism plays a significant role too. Detroit’s white flight exploded in the 1950s and ‘60s, after courts struck down local and federal policies that had allowed segregated housing. That was followed by middle-class flight on the part of blacks and whites as crime endemic to high-poverty, high-unemployment neighborhoods began spreading. It’s significant to note that Detroit’s inner-ring suburbs have been picking up African-American populations as young Detroit families seek safety, stability and more reliable schools. As they run out of the city, its vast socioeconomic problems become even more distilled, more pronounced.

Detroit stands as the reverse image of what we think a modern American city should be. Where most have a few “bad” neighborhoods, Detroit has a few “good” neighborhoods, and they are eroding quickly with the middle-class exodus. Working-age Detroiters face chronic unemployment in a dying industrial economy. The city has been buffeted by generations of racial friction and let down by governmental institutions that have failed at basic tasks, from education to crime prevention.

One in three Detroiters, triple the national rate, lived below the federal poverty line in 2007 ― before the economic crisis and auto industry bankruptcies and bailouts ― making Detroit the poorest of the nation’s big cities. Detroit’s per capita 2009 income was estimated at $15,310, compared with a national rate of $27,041 (Los Angeles’ was $27,070). And that was when the population was estimated to be more than 900,000 people.

To tweak the adage about how it takes a village to raise a child, it will take a nation to save a city. So, as a nation, and as a mature society, what are we going to do about Detroit?

By Scott Martelle

Scott Martelle’s “The Fear Within: Spies, Commies, and American Democracy on Trial,” will be published in May. ― Ed.

(Los Angeles Times)

(McClatchy-Tribune Information Services)