Venezuela earthquakes expose deadly warning for California's urban vulnerability

Two major earthquakes, a magnitude 7.2 foreshock and a magnitude 7.5 mainshock, struck Venezuela’s northern coast 39 seconds apart, ripping through La Guaira and Caracas and killing about 235 people as rescuers kept searching collapsed buildings. The U.S. Geological Survey’s PAGER model flashed a red alert before the full toll was known, estimating a possible death range from 10,000 to 100,000 and giving the event a 42% chance of killing at least 10,000 people.

Venezuela declared a state of emergency after the back-to-back quakes, which shook along the San Sebastián fault system and were the country’s strongest earthquake sequence since 1900. Thousands were injured. Aerial footage and live reporting from the region showed damaged coastal neighborhoods, battered apartment blocks and rescue crews working through the wreckage.

Engineers and seismologists have long warned that older non-ductile concrete, soft-story and unreinforced brick buildings can fail violently in a major quake, especially in dense neighborhoods where people have little time to escape. Caracas has often been compared with Los Angeles and San Francisco because the building stock, street patterns and concentration of older structures create similar risks when strong shaking hits.

Los Angeles has mandatory retrofit programs for some pre-1978 soft-story and non-ductile concrete buildings, and the city’s Department of Building and Safety gives owners timelines to submit evaluations, file retrofit plans and finish construction. A prior Los Angeles Times project found about 6,000 Los Angeles-area buildings that still needed retrofit, and Los Angeles County still does not have a centralized public database that lists every quake-vulnerable building.