The U.S. has lost more than 5 million manufacturing jobs since 2000.  Lately, it's been a slow climb back.

One state that was hit hard by this industrial decline is Pensylvania.  According to Bureau of Labor Statistics data, Pennsylvania lost more than 200,000 manufacturing jobs between 2000 and 2010.

According to Troy Graham at the Philadelphia Inquirer, this decline in Pennsylvania's manufacturing sector didn't involve just the loss of good-paying manufacturing jobs.  Graham reports that a number of factories have sat empty for years, inviting vandalism and theft as well as environmental problems:

After the owner of Gryphin Coatings closed his Port Richmond plant, an army of scrappers and vandals broke out the windows, kicked in the doors, and carted off just about every piece of salable metal.

Residents lived in constant fear of environmental catastrophe or a disastrous fire, especially after a scavenger caused a chemical leak that forced the evacuation of several homes.

Although the Gryphon Coatings plant was eventually demolished, the problems of other rusting industrial hulks proved more calamitous:

The potentially disastrous effects of aged, empty factories was cast in stark relief last month, when firefighters Robert Neary and Daniel Sweeney died in a collapse during a fire at a century-old former hosiery mill in Kensington.

That was one of at least six large fires - some calamitous - in nearby vacant factories in the last two decades. One neighborhood activist likens the buildings to "bombs waiting to go off."

The problem is more widespread than expected, and Graham reports that the full number of crumbling factories in and around Philadelphia is unknown, though city records show "2,808 parcels classified as either vacant industrial land or industrial land with a building that was in below-average to inferior condition."

Worryingly, the problem isn't limited to Pennsylvania.  As Rep. Betty Sutton (D-OH) reported last fall, the U.S. lost 56,190 factories over the past decade, an average of 15 factories closing each day.

One can only wonder at the large scale of decaying old factories scattered throughout the U.S. and the potential for problems like those experienced in Philadelphia.

Read more.