MEXICO CITY – After thousands died in the 1985 earthquake in Mexico's capital, experts rewrote building codes hoping to prevent another catastrophe.
But they left out a crucial reform: a ban on a construction technique that new data shows caused almost two-thirds of the building collapses in last month's quake.
Several prominent engineers say had Mexico City outlawed this building technique, dozens of lives likely could have been saved on Sept. 19. The magnitude 7.1 quake killed 369 people and covered avenues in rubble.
Data compiled by a Stanford University professor shows that 61 percent of the buildings that fell were designed with a construction method called flat slab, in which floors are supported only by concrete columns, without beams. That design is now forbidden in some other places.