LA County has rapidly expanded over the last several decades, adding more and more buildings to the landscape.

But Southern California is due for a major earthquake. And a new analysis by the LA Times shows more than a thousand of LA's older, concrete buildings are at risk of collapse when an earthquake strikes.

According to the Times, officials have known about such dangers for more than 40 years but have failed to force owners to make their properties safer.

Reporter Ron Lin has more of the story.