Note the eyewitness reports of people being thrown in the air in the article (accelerations > 1g). Also, interesting that the television building that collapsed was concrete rather than steel frame encased in concrete (assuming I understood that correctly). Caution: I am not an engineer. I have heard some presentations at SCEC meetings by engineers. My take on this is that the posters and talks at the Southern California earthquake center applied to 20 story steel frame buildings. I assume, but could be wrong, that the duration of shaking on such buildings is important to whether they collapse or not. For 5 story concrete buildings, it may not have to shake as long: the peak accelerations at certain frequencies may be more imporatant and a few seconds may be enough.

It is kind of important that someone correct me if they think I am wrong:
In my (limited) understanding, this is important to Los Angeles. Because of the sedimentary basin, there can be large ground motions for extended periods (2 minutes) from relatively distant quakes, such as on the San Andreas.

It is possible, but I could be terrobly wrong, that the buildings of a couple of stories might do better in such a quake and badly on a local quake (like Northridge, or the Santa Monica-Hollywood fault they mention).
Chris