What happens when a once-great city slowly dies

I was in a store yesterday which was running a temporary display of framed old-timey pictures of Detroit in the 1920's, 30's, and 40's. One was of the Michigan Central Station, which in its heyday, was a grand structure:

"Designed by the renowned architects Warren & Wetmore and engineers Reed and Stem, that also designed the Grand Central Station in New York City, the Michigan Central Station opened in 1913 with a final price tag of $15 million and consisted of a 3 story train station with an 18 story office tower. The building contained 7,000 tons of structural steel, 125,000 cubic feet of stone, and 7 million bricks.

As one would enter off Roosevelt Park, they would walk into the buildings center piece, the main waiting room. The 54.5 feet tall waiting room modeled after a roman bath, stretches the length of the building and is decorated with Guastavino arches, columns, and three arched 21 by 40 feet windows flanked by four smaller windows. Beyond the waiting room, you could buy your ticket from one of the many ornate ticket counters, or walk down the 28 feet tall arcade to visit a newsstand, drugstore, cigar shop, or barbershop.

In addition to the arcade and waiting room, the station featured a restaurant with vaulted ceilings, a main concourse with a copper skylight,and a lunch counter."

Today, I find a heartbreaking pictorial from the UK's Guardian/Observer. Slides 6 and 16 in the photo set show the Michigan Central terminal in a sadly dilapidated state. A Google search returns even more decay, such as this image of the terminal's rail bed:

We've lost so much.