Even some new construction is being questioned. At least two new mixed-use high-rises are being built in Hollywood at a cost of hundreds of millions of dollars. New mapping by the state indicates they sit on top of two newly discovered earthquake faults. The developers say geological tests have shown no evidence of an active fault, but opponents see the discovery as validation.
"This is an arrow in the heart of the most ill-conceived, dangerous and reckless project in the recent memory of the city of Los Angeles, probably in Los Angeles history," said attorney Robert Silverstein, representing a group of residents suing to stop construction.
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The city has recently moved to borrow a seismologist from the U.S. Geological Survey for a year to address issues of private construction. It is also using the anniversary to remind people to prepare for the next quake. Residents are supposed to have a three-day supply of food and water handy, plus batteries and flashlights.
Jeff Edelstein runs SOS Survival Products in Van Nuys, not far from the epicenter of the 1994 quake, but he is seeing only a slight pickup in business. "There's still a state of denial," he said.
Whatever the case, at some point in the future, Californians will get another wake-up call.
"There's a better than 50-50 chance that we will have a catastrophic earthquake in California that will kill thousands of people," warned Gov. Jerry Brown last week. "The people of LA should be cautious, because earthquakes are just around the corner."
—By CNBC's Jane Wells; Follow her on Twitter: