Southern California could suffer the most deadly and damaging natural disaster in U.S. history if the Puente Hills fault zone beneath Orange and Los Angeles counties ruptured and produced a magnitude 7.2 or larger earthquake, scientists said Wednesday.
As many as 18,000 people could die and 120,000 people could be injured if the poorly understood fault broke on a weekday afternoon, researchers said during a news conference led by the U.S. Geological Survey. Economic losses could surpass $250 billion, dwarfing the $44 billion in damage caused by the 1994 Northridge quake.
"This is an absolute worst-case scenario," said Ned Field, a USGS researcher who teamed with the Southern California Earthquake Center in Los Angeles to produce a range of damage estimates published in the journal Earthquake Spectra.
"This is a very rare type of event; the odds of dying of a heart attack are much higher," Field said. "But the fault has produced four quakes in the magnitude-7.2-to-7.5 range during the past 11,000 years. We ran damage scenarios because this fault lies beneath a very urban area."
As was the case with Katrina, experts say the federal government hasn't done enough to prepare.
"There's not enough money to carry out the research and implementation programs that need to be put into place," said Susan Tubbesing, executive director of the Earthquake Engineering Research Institute in Oakland, Calif. "If funds were available, if these were higher priorities, these kinds of things could be addressed now — before an earthquake."
California has been hit by significant quakes about every 15 years over the past century. Experts say there's a better-than 60 percent chance that a quake with a magnitude around 6.7 will hit Southern California or the Bay Area within decades.
"The reality is when you have a disaster of that proportion, you need the federal government," Los Angeles Mayor Antonio Villaraigosa said Wednesday in Washington, where he was meeting with federal officials. "I think the question is, is the federal government prepared to provide the resources that we need? I think that, clearly, by what we've seen in Louisiana, the jury's out."