It’s a problem that won’t go away anytime soon. As Connecticut tries to right its economy and reinvent itself as a friendly place to do business, the state is also grappling with what to do with structural vestiges from a different economic era.

Several decades ago, it was the mills. Once those manufacturing jobs became obsolete, or were moved either to southern states or overseas, corporations and towns had to find suitable uses for the hulking structures. Some towns, such as Beacon Falls, have done a commendable job converting them into living space. Others, such as Torrington and Winsted, have been less successful at finding uses for the abandoned mills.

Now we can add to that list of obsolete structures. Those sprawling corporate office campuses that have sprung up since the mills died are rapidly becoming a thing of the past, as The Courant’s Ken Gosselin documented recently.

Chief among them is The Hartford’s 641,000-square-foot office building set on 173-acres in Simsbury. The sheer size of the anachronistic campus is staggering: it’s as big as four Wal-Mart supercenters and the square footage is half that of the Chrysler building in Manhattan. Sadly, the venerable insurance company is in a cost-cutting mode (who isn’t these days?) and has put the campus on the block.

To give you an idea of the economic impact such a facility has on a relatively small town like Simsbury, The Hartford pays $1.6 million a year in property taxes to a town that has an $83 million budget. The Hartford employs almost half of Simbury’s 3,315-person workforce at an annual expense to the company of $8 million per year. Perhaps shockingly, the Simsbury campus opened in 1984 at a cost of $50 million, which gives you an idea of how quickly the market for office space can change.

And there are numerous other examples cited by Gosselin. Aetna couldn’t find a use for its 1.3-million-square-foot campus in Middletown and so demolished it in 2011. The resulting vacant lot remains for sale.

Pfizer is demolishing a 750,000-square-foot research center in Groton. The town of Ridgefield bought the shuttered the Schlumberger-Doll Research Center in 2011 for $7 million, but hasn’t been able to do much with it and is trying to flip the property.

To be sure, there are some exceptions to the trend. The architecturally distinguished Union Carbide campus in Danbury was successfully sold for half its construction price in 2007, despite being in a state of flux for much of its existence. And a new research center is being opened in Farmington. But the state had to bribe Jackson Laboratories to the tune of $291 million in borrowed money to get the company to make the move from Maine to Connecticut.

In addition to the general downsizing trend, a variety of factors is contributing to the decline of these sprawling corporate behemoths. Telecommuting has become more commonplace and has reduced the demand for office space. And technological advances have obviated the need for the legions of workers who performed time- and space-consuming data entry tasks.

But suburban corporate headquarters aren’t the only endangered species in the neighborhood. Online shopping has hurt the bottom line of shopping malls. As recently as 1990, 19 shopping malls were built in America. But there hasn’t been new one built since 2006.

The more upscale malls such as Westfarms are doing fine but mid-market affairs like Buckland Hills are having a tougher time maintaining market share, researcher Ryan Severino told John Dankosky on WNPR.

So what do we do with these monstrosities once they’re no longer useful? Perhaps the best suggestion came from a caller to Dankosky’s show who owns a farm near Buckland Hills. Downsize the malls to one floor and convert the top floor to affordable housing for the mall workers, many of whom toil away at little more than minimum wage.

Perhaps the same could be done to some of these empty corporate hulks. Mixed-use residential and retail might be just the tonic needed to bring back a sense of community in some of our fragmented suburbs.

Contributing op-ed columnist Terry Cowgill blogs at ctdevilsadvocate.com and was an editor and senior writer for The Lakeville Journal Company. Follow him on Twitter @terrycowgill.