In eight days, when a four-ton wrecking ball begins to pummel it like a Broad Street Bully, the Spectrum, a landmark arena that launched a sporting renaissance in Philadelphia, will crumble into oblivion after months of pre-demolition ballyhoo but almost no opposition.

Its impending demise points out something contradictory about this sports-mad city: No matter how rich their history, Philadelphia venues such as Convention Hall, Connie Mack Stadium, Municipal Stadium, the old Arena, and now the Spectrum seem to be expendable in a way that more historically authentic or architecturally appealing structures often are not.

While threats to old and ornate buildings or to prized works of art (remember the battles that kept Thomas Eakins' The Gross Clinic and Maxfield Parrish's Dream Garden in Philadelphia?) frequently ignite fruitful outrage, the disappearances of these urban sports palaces rarely has.

Why?

"I'm not quite sure," said Scott Doyle, director of grants and state historical markers for the Pennsylvania Historical and Museum Commission. "But there has been no concerted efforts that we're aware of to preserve the Spectrum. And there weren't any when Municipal/JFK Stadium came down, either."

Perhaps it's because of their disposable nature. In sports, after all, the old traditionally yields to the younger and sleeker. Connie Mack Stadium was replaced by Veterans Stadium, which gave way to Citizens Bank Park. The Spectrum followed Convention Hall, before its own demise was guaranteed by the CoreStates Center (now the Wells Fargo Center).

"A lot of it comes down to money," said Philadelphia-based urban planner Sandy Sorlien. "We love the Spectrum and places like that for what took place inside. But it's a pretty unremarkable building and if it were preserved, would it attract a lot of tourists? Probably not. It's almost always cheaper to tear down and start over."

Or it could be, as Sorlien suggested, the fact that many of Philadelphia's venues - Municipal Stadium, the Spectrum and, to a lesser extent, Convention Hall - weren't located in neighborhoods, which eliminated one potential group of supporters.

No one loves them

What makes this passivity even more surprising is that these ballparks and arenas have had broad civic connections. What Philadelphian, for example, never attended a game, concert or ice show at the Spectrum? What local fan hasn't heard his or her father talk about Shibe Park (later Connie Mack) or the Army-Navy game at Municipal Stadium?

Author Bruce Kuklick, in his 1991 history To Every Thing a Season: Shibe Park and Urban Philadelphia, notes how this abandonment of sporting venues could be construed as a generation "squandering its heritage and demolishing places where the public past is manifest."

It's not like there isn't precedent for sports-preservation efforts. Groups aimed at saving prized sports venues have risen elsewhere.

In Pittsburgh, there recently were several well-organized, but failed, efforts to save the longtime home of the NHL's Penguins, Mellon Arena.

"And there certainly have been more significant events at the Spectrum than at Mellon," Doyle said.

At the University of Maryland, alumni and others have made it known they want historic Cole Field House preserved. And a community church came forward to save Los Angeles' Forum.

But not in Philadelphia.

"No one loves these buildings," Sorlien said. "It might be a different story if they were located in a neighborhood, like Wrigley Field" is in Chicago.

In 2007, the proposed demolition of two neglected North Broad Street buildings whose only noteworthy features appeared to be their grimy facades inflamed the city's preservation community. The outcry, which nonetheless failed to save the structures, was in marked contrast to the near-silence that just two years earlier met the end of Convention Hall.

That 74-year-old West Philadelphia arena, which had hosted four historic political conventions; a Beatles concert; speeches by Franklin Delano Roosevelt, Pope John Paul II, the Rev. Dr. Martin Luther King Jr., and Nelson Mandela; legendary hoops duels between Wilt Chamberlain and Bill Russell; and decades of sporting events and graduations, also disappeared with hardly a whimper of protest.

And though it's now recalled wistfully as a green cathedral, a martyr to modernity, the abandoned Connie Mack Stadium had become such a hazardous eyesore that North Philadelphia neighbors begged city officials to tear it down. Finally, in the spring of 1976, after demonstrators blocked Lehigh Avenue, Mayor Frank Rizzo gave the unsentimental order to "tear the . . . thing down!"

The Arena, at 45th and Market, and Municipal Stadium, where Jack Dempsey and Gene Tunney fought once and Army and Navy battled innumerable times, suffered similarly inglorious and surprisingly unremarked-upon fates.

"The Spectrum and some of these other places aren't the kinds of beautiful buildings you would normally think about preserving," Sorlien said. "What's special about them is what took place inside, what lives on in memories. And the reminders of those kind of things can be transferred to another site."

Think of Citizens Bank Park, where the Phillies' Wall of Fame from the Vet and the statue of Connie Mack from outside the stadium named in his honor have been relocated.

Not around for long

Whether or not you believe the Spectrum deserves to die, it did have a surprisingly short life.

When it opened in the fall of 1967, the new home of the 76ers and Flyers helped lend a sheen of respectability to those franchises, each of which would embark on eras of great success within a decade.

Of the arenas in the then-12-team NBA at the close of the 1967-68 season, eight, not counting the Spectrum, still exist, including the fourth Madison Square Garden, which opened in February 1968.

Detroit's Cobo Arena, Cincinnati Gardens, the Baltimore Civic Center, the Forum, San Francisco's Cow Palace, the Seattle Center Coliseum, and the San Diego Sports Arena have all lost their major tenants, but have been refitted for continued use.

And the only three circa 1967-68 NBA buildings to have been demolished since then were all at least 34 years older than the Spectrum - the 1928 Boston Garden, the 1929 Chicago Stadium, and the 1934 Kiel Auditorium in St. Louis.

"I'm not certain about all of them, but a majority of those were located in downtowns or in neighborhoods, where it's easier to come up with another use," Sorlien said.

One place in Philadelphia, however, where a sports past has been preserved is the Blue Horizon, the 1865 edifice on North Broad that has been a boxing mecca since 1961. While it still features fight cards, the venue also hosts weddings and parties.

Another example is the University of Pennsylvania, where Franklin Field and the Palestra, two aging but legendary venues, are not only still in existence but continue to be used by the school's athletes.

That could have changed 20 years ago, according to Penn athletic director Steve Bilsky, when there were discussions about tearing down Franklin Field, now 115 years old.

"They had to decide whether to spend tens of millions to make sustainable changes or tear it down," Bilsky said. "Princeton, at about that same time, was faced with a similar decision about Princeton Stadium.

"Princeton decided to tear it down and build a new stadium, but Penn said, 'No, we've got to do what it takes to keep Franklin Field.' " The Palestra, built of brick and steel in six months during 1927, is a solid enough structure "to last millions of years," Bilsky said.

"The challenge is keeping it maintained and adding certain amenities from time to time," he said. "I can't imagine anyone ever suggesting that we tear down the Palestra. Not without going through all kinds of committees here."

Contact staff writer Frank Fitzpatrick at 215-854-5068 or ffitzpatrick@phillynews.com.