Despite some determined signs of hope, the city remains in free fall 40 years after the riots that tore it asunder

Among a long list of favourite criminal things to do in Detroit is the stealing of copper. Copper wiring is a satisfying find, as is copper piping, ripped out of the city's Victorian homes or the once-magnificent beaux-arts train station. In a city with one-third of its population living below the poverty line, in a place that America abandoned long ago, there are few rewards greater than copper eavestroughs. This year marks the 40th anniversary of the Detroit riots, an uprising of the poor - black and white - that ended with 43 people dead. Since then, the city has lost about half of its population, now estimated at 890,000. Splendid, stately homes have fallen down; art deco towers are half-empty. Academics and professionals who refuse to leave downtown hire private security firms to protect their cars, their homes and their eavestroughs.

America loves winners. But behold the depth of blight and despair within Detroit, and understand this: Urban losers have no place in America.

From Mumbai to Calgary to Los Angeles, the story of the 21st-century city depends on intoxicating evidence of growth and economic triumph. But to speak of urban failure makes us uncomfortable, like a doctor unable to talk meaningfully to a dying patient.

My first glimpse of Detroit is from the glass prow of the Art Gallery of Windsor. Windsor's own elegant riverfront meanders gracefully along the Detroit River. Directly across the choppy waters is a skyline that once belonged to a great city. At night, viewed from afar, Detroit is a muscular, glittering composition. There are some splendid loft conversions now completed in the city; and a $500-million (U.S.) investment by General Motors in the Renaissance Center (a hulking series of towers that originally turned its concrete back on the Detroit River) has opened a winter-garden atrium to a reinvented riverfront.

Walking along Woodward Avenue, a grand civic boulevard lined with skyscraper masterpieces from the 1920s, it's possible to imagine the city as the economic giant where Henry Ford launched his dynasty and Detroit architect Albert Kahn designed hundreds of his factories.

But the era of Fordism has come to an ugly end. And clearly there is no sympathy or remorse for what was, or what could have been. Like Carthage, Detroit has fallen. The Michigan Central Station (1913) - designed by Warren & Wetmore, Reed & Stern, the architects of New York's Grand Central Terminal (also 1913) - has had every one of its 600 windows bashed out. Graffiti rages over its once-gorgeous Corinthian columns and pilasters. Walking past the ghetto trees sprouting up for acres in neighbourhoods that once resembled Toronto's posh Rosedale, and hearing about the failure of the public schools to educate those who remain, I believe Detroit could continue to fall for a long while. Fixing the sidewalks cannot bring it back. Nor can the hippest loft conversions. The downfall of Detroit has to do with a poverty that is as deep as the city's historic racial tensions.

Every month, about 1,000 people leave Detroit. Most of them are African-Americans who move to the inner ring of the city's suburbs in search of better schools, safer neighbourhoods and lower taxes. Long-time residents of the suburbs will proclaim, as a badge of honour, that they haven't stepped foot in downtown for 35 years.

And their absence is obvious. In the heart of what used to be a bustling neighbourhood of immigrants, public-housing projects are boarded up, and fields of urban prairie surround beat-up, two-storey clapboard houses. The mayor of Detroit, Kwame Kilpatrick, reportedly drives around his sad city in a fleet of Cadillacs, enough for him and his security guards. Though his credibility has been debated, Kilpatrick has managed to see through a public-private initiative to construct Campus Martius (2004), a popular park with skating rinks and outdoor screenings of movies, and he has designated six neighbourhoods for revitalization. The $12-million restoration of the Fox Theatre has also been significant for the city. And Diamond + Schmitt Architects Inc. of Toronto designed a major addition to the historic Symphony Hall, tripling the size of the facility so that the newly named Max M. Fisher Music Centre (2003) can seduce a broader audience into its performance facilities.

Lafayette Park, planned by Ludwig Hilberseimer, with its glass-and-steel buildings designed by the great modernist Mies van der Rohe, was a gem of urban renewal when it went up in the early 1960s, and functions still today as a model of racial and economic diversity. It's in the downtown's east side, in what used to be hardcore black slums, now a mix of subsidized high-rise towers, exquisitely detailed two-storey townhouses and one-storey courtyard houses spread over an idyllic, lushly planted 78-acre (32-hectare) park setting.

Members of its housing co-operatives are delighted to speak to a visitor from Canada, and keen to tell of recent, sensitive upgrades to the buildings - some of the co-ops now enjoy thermal windows and geothermal heating - accomplished while respecting the strictly minimal international style of Mies. Standing there among Lafayette's now-mature maple and locust trees, it's possible to lose sight of the decoupled city just beyond, on the other side of the rail tracks.

If you're looking for urban grit, Detroit is the place to get it. In Brush Park, once a bucolic urban retreat for the elite, with gracious brick houses featuring stone turrets and generous front hallways, a kind of urban prairie has taken over where buildings once stood. It's quiet here, except that, way in the distance, across the field, is the sound of hammering - lone pioneers determined to fix up one of the mansions turned squalid from years of neglect.

Author Peter Markus has worked for years teaching writing to the children of Detroit's inner-city schools and, earlier this year, was the writer-in-residence at Wayne State University in Detroit. He sees some cause for optimism, not despair. When he and his wife moved into a brownstone in the tough neighbourhood of Cass Corridor during the mid-1990s, they were greeted by a man who banged on the hood of their car and hollered, "No white people allowed in the Corridor!" But for five years, Markus resisted, and was glad for his time there - a bit like his grandparents from Hungary, who stayed put in Detroit's downtown "when everyone else split."

Can Detroit turn itself around? Possibly. Hopefully. But it's not likely in the near future. And it's unlikely the three casinos opening within the downtown will provide much of an elixir. The MotorCity Casino, with 100,000 square feet (9,290 square metres) of gaming space plus a luxurious hotel, has recently opened: Now, locals can enjoy a $7 breakfast that comes with the possibility of losing their milk money, or, with the swipe of their gaming plastic, an entire paycheque. "The scale of what's being constructed downtown is not able to stem the net loss of population," says George Galster, professor of urban affairs at Wayne State, who has lived in Detroit for 11 years. "Crime has been getting worse and worse and worse since about 2000, when our economy crashed locally, and it hasn't improved since. There are a lot of desperate, desperate people in Detroit, and a lot of that is reflected in the upsurge of crime."

Detroit - like Buffalo, like New Orleans, like so many American cities that are largely ignored - does not command the attention of Washington.
Solutions, if they are to be found, will have to be locally crafted. What is to become of a city that measures 357 square kilometres of mostly low-scale houses spread over growing patches of vacant land? Despite the ravages suffered by the place, the word "downsize" is verboten. "If you say 'downsize,' politically, you're dead," warns Robin Boyle, chair of Wayne State's department of geography and urban planning, who nonetheless imagines a smaller, more compact Detroit with lots of open space: There are gardening collectives to be found here, and urban farms to be made from abandoned tracts of land. There's room enough for people to stake their claim to an unconventional kind of urbanity.
Once you get past the myth of America, the sky is the limit. Just don't put copper in your new, urban farmhouse.