LOS ANGELES -- Hours beforethis past week, a smaller quake jolted the Los Angeles area. It was a reminder that the so-called "big one" will eventually hit southern California.
Scientists say many Californians have a false sense of security regarding earthquakes.
As engineers survey the destruction in Mexico City, a lot can be learned from the buildings that survived the magnitude 7.1 earthquake -- and the ones that did not.
For example, one concrete apartment building didn't have enough steel rebar embedded in the support columns.
"That is actually a classic failure -- and it's common construction," said California Seismic Safety Commissioner Kit Miyamoto.
And it's common construction, especially in Los Angeles. Engineers call it a "soft story" building, where the ground floor is often used for parking.
In one video, you can actually see the moment and the location of the failure in that building.
"Exactly. If you see that carefully, the corner columns start essentially buckling, vertical rebar is bucking outward and that caused the collapse of the ground floor," Miyamoto said. "It's pancaking the ground floor."
Miyamoto is traveling to Mexico City next week to assess the damage.
"It just the understanding of what happened there and what were the lessons we can learn in California," Miyamoto said.
Last year in Los Angeles, he said "unreinforced masonry buildings ... without any seismic strengthening is essentially what I call a 'death box.'"
The city is now targeting more than 13,000 small residential apartment buildings and nearly 1,500 concrete buildings that still need reinforcement.
"LA is essentially now leading the nation, leading the whole world for this type of the seismic strengthening," Miyamoto said. "But are we prepared completely? No, we are not. I think we can do so much more."
Once all the vulnerable concrete buildings here in Los Angeles are inspected, owners will be given 25 years to reinforce the structures.