The Seismic Defect Lurking in Some California High-Rises

A steel structure encases the exterior of One Maritime Plaza in San Francisco, May 16, 2018. The U.S. Geological Survey has published a list of potentially earthquake-vulnerable structures in San Francisco, nearly a quarter-century after a crucial flaw was discovered in a common construction technique; this building was retrofitted to make it stronger in the event of an earthquake. (Jim Wilson/The New York Times)