BALTIMORE -- Shivihah Smith's East Baltimore neighborhood, where he lives with his mother and grandmother, is disappearing. The block one over is gone. A dozen rowhouses on an adjacent block were removed one afternoon last year. And on the corner a few weeks ago, a pair of houses that were damaged by fire collapsed. The city bulldozed those and two others, leaving scavengers to pick through the debris for bits of metal and copper wire.
"The city doesn't want these old houses," lamented Mr. Smith, 36.
For the Smiths, the bulldozing of city blocks is a source of anguish. But for Baltimore, as for a number of American cities in the Northeast and Midwest that have lost big chunks of their population, it is increasingly regarded as a path to salvation. Because despite the well-publicized embrace by young professionals of once-struggling city centers in New York, Seattle and Los Angeles, for many cities urban planning has often become a form of creative destruction.
"It is not the house itself that has value; it is the land the house stands on," said Sandra Pianalto, the president and chief executive of the Federal Reserve Bank of Cleveland. "This led us to the counterintuitive concept that the best policy to stabilize neighborhoods may not always be rehabilitation. It may be demolition."
Large-scale destruction is well known in Detroit, but it is also underway in Baltimore, Philadelphia, Cleveland, Cincinnati, Buffalo and other cities at a total cost of more than $250 million. Officials are tearing down tens of thousands of vacant buildings, many perfectly habitable, as they seek to stimulate economic growth, reduce crime and blight, and increase environmental sustainability.
A recent Brookings Institution study found that from 2000 to 2010 the number of vacant housing units nationally had increased by 44 percent, or 4.5 million. And a report by the University of California, Berkeley, determined that over the past 15 years, 130 cities, most with relatively small populations, have dissolved themselves, more than half the total ever recorded in the United States.
The continuing struggles of former manufacturing centers have fundamentally altered urban planning, traditionally a discipline based on growth and expansion. Today, it is also about disinvestment patterns to help determine which depopulated neighborhoods are worth saving; what blocks should be torn down and rebuilt; and based on economic activity, transportation options, infrastructure and population density, where people might best be relocated. Some even focus on returning abandoned urban areas into forests and meadows.
In all, more than half of the nation's 20 largest cities in 1950 have lost at least one-third of their populations. And since 2000, a number of cities, including Baltimore, St. Louis, Pittsburgh, Cincinnati and Buffalo, have lost around 10 percent; Cleveland has lost more than 17 percent; and more than 25 percent of residents have left Detroit, whose bankruptcy declaration this summer has heightened anxiety in other postindustrial cities.
The result of this shrinkage, also called "ungrowth" and "rightsizing," has been compressed tax bases, increased crime and unemployment, tight municipal budgets and abandoned neighborhoods. The question is what to do with the urban ghost towns unlikely to be repopulated because of continued suburbanization and deindustrialization.
"In the past, cities would look at buildings individually, determine there was a problem, tear them down and then quickly find another use for the land," said Justin B. Hollander, an urban planning professor at Tufts University. "Now they're looking at the whole DNA of the city and saying, 'There are just too many structures for the population we have.'"
Cleveland, whose population has shrunk by about 80,000 during the past decade to 395,000, has spent $50 million over the past six years to raze houses, which cost $10,000 each to destroy, compared with $27,000 annually to maintain.
Some neighborhoods have lost two-thirds of their residents since 2000. There are so many vacant lots that the city, now home to more than 200 community gardens and farms, zones for urban farms and allows people to keep pigs, sheep and goats in residential areas. A vineyard has popped up as well.
Two miles northwest of the Gateway Arch in St. Louis, which has at least 6,000 vacant buildings, is an uninhabited deciduous forest where a sprawling 74-acre housing development once stood before the city demolished it because so few people lived there.
At least one city that has taken a pioneering approach to confronting diminution has found that accepting shrinkage does not mean problems go away.
Youngstown, Ohio, once a bustling steel city of 170,000 but now with only 66,000 people, has sought to head off collapse by tearing down thousands of vacant houses -- 3,000 so far and 10 more each week.
But while the city had planned on a stable population of 80,000, more than 1,000 people move away every year, leaving behind 130 additional empty homes in addition to the city's 22,000 vacant properties and structures. Four thousand of those homes are in dangerous condition, according to the city, but each demolition costs $9,000 and the city has yet to decide whether to close nearly abandoned neighborhoods to try to save money.
"It's almost anti-American to say our city is shrinking," said Heather McMahon, the executive director of the Mahoning Valley Organizing Collaborative, a Youngstown community group.
"But if we're going to survive as a city and not go bankrupt like Detroit, we're going to have to figure something out."