The recent earthquake in Chile was the fifth largest ever recorded and the U.S. Geological Survey is investigating damaged buildings there to better understand our own California. "One immediate observation from Chile's earthquake that could find its way into US building code is on confining reinforcement, says Maffei, who is on the committee that decides building code in California. Confining reinforcement is meant to keep vertical bars from bucking, but the design proved insufficient in Chile. Maffei says he would consider requiring confining reinforcement along a greater length of the wall. In preparing an earthquake-proof building code, engineers must also take into account the land the building sits on. Chile provides a case study in this, too. While the center of Santiago withstood the quake relatively well, on the outskirts of the city the metropolitan area of Maipu fared much worse because it sits atop soft volcanic ash, which amplifies the motions of the earthquake. Several apartment complexes in Maipu will have to be demolished."