It's not often that Hollywood loses one of its great icons — an icon whose career spans decades and runs a gamut of some of America's best-known films. From Grease to Terminator 2, from Roadblock to Gone in 60 Seconds, the unlikely star never became a legend despite never really getting top billing.

"It's not the lead character," says Dan Koeppel, a Los Angeles-based author who writes about transportation. "It plays a supporting role, and that's what it should be doing."

The icon, of course, is not an actor at all. It's a bridge: the Sixth Street Bridge, also known as the Sixth Street Viaduct, in LA.

And it's getting torn down, thanks to a kind of concrete cancer called alkali-silica, which is causing too many cracks and crumbles. The bridge was one moderate earthquake away from collapse, according to the California Department of Transportation. Its demolition, which is slated to occur in stages, began on Feb. 5.