More than 1,000 old concrete buildings in Los Angeles and hundreds more throughout the county may be at risk of collapsing in a major earthquake, according to a Los Angeles Times analysis. By the most conservative estimate, as many as 50 of these buildings in the city alone would be destroyed, exposing thousands to injury or death.
A cross-section of the city lives and works in them: seamstresses in downtown factories, white-collar workers in Ventura Boulevard high-rises and condo dwellers on Millionaires' Mile in Westwood.
Despite their sturdy appearance, many older concrete buildings are vulnerable to the sideways movement of a major earthquake because they don't have enough steel reinforcing bars to hold columns in place.
Los Angeles officials have known about the dangers for more than 40 years but have failed to force owners to make their properties safer. The city has even rejected calls to make a list of concrete buildings.
In the absence of city action, university scientists compiled the first comprehensive inventory of potentially dangerous concrete buildings in Los Angeles.
The scientists, however, have declined to make the information public. They said they are willing to share it with L.A. officials, but only if the city requests a copy. The city has not done so, the scientists said.
More urban stories.
Recent earthquakes have spotlighted the deadly potential of buildings held up by concrete. A quake in Christchurch, New Zealand, more than two years ago toppled two concrete office towers, killing 133 people. Many of the 6,000 people killed in a 1995 earthquake in Kobe, Japan, were in concrete buildings.
In 1971, the Sylmar earthquake brought down several concrete structures, killing 52. Twenty-three years later, the Northridge earthquake wrecked more, including a Bullock's department store and Kaiser medical office.
Seismologists said a quake bigger than Northridge and Sylmar is overdue.
"We know darn well that if a bunch of people die, there will be lots of stories, lots of reports, things will change," said Thomas Heaton, director of the Earthquake Engineering Research Laboratory at Caltech. "But the question is, do we have to have lots of people die in order to make this change?"
In the Roaring '20s, concrete buildings helped transform the Los Angeles skyline, as office towers and apartments rose from the city's landscape.
By the 1970s, canyons of concrete towers lined some of L.A.'s most famous streets: Wilshire, Hollywood, Sunset, Ventura, Main and Broadway. They include landmarks such as the Capitol Records tower, the Hollywood Plaza apartments and the W Hotel in Westwood, according to city records.
A team of reporters mined thousands of city and county records to identify older concrete buildings. The Times found more than 1,000 buildings in Los Angeles and hundreds elsewhere in the county that appeared to be concrete.
Reporters walked through seven L.A. business districts to gauge the accuracy of the list. They pulled building permits and sent questionnaires to dozens of property owners, asking them to review the details. In these areas, The Times found 68 older concrete buildings, according to public records. Of those, just seven had been retrofitted, or strengthened to survive large earthquakes. The reporters' work covered a fraction of the older concrete structures in the city.
The survey showed the difficulties of accurately identifying concrete buildings. Some city records didn't specify the construction materials used. Some buildings that appeared to be made of concrete turned out to be steel framed, while others that appeared to be brick or steel were concrete.
Hollywood _ which is bisected by a fault capable of producing a 7.0 earthquake _ has one of the biggest concentrations of concrete buildings. In a few blocks around Hollywood Boulevard and Vine Street, The Times found 14 concrete structures built before 1976, when city codes started requiring more steel rebar. Only three have been retrofitted.
The story is much the same on a stretch of Ventura Boulevard in the Encino area. The Northridge quake battered several concrete buildings in the district, including a 10-story hotel. Owners spent $4 million to better protect it in an earthquake. Out of 10 concrete buildings on that section of the street, only the hotel and one other structure have been strengthened.
In two downtown neighborhoods, along Broadway and Santee Street, The Times found 17 concrete buildings. None had a record of retrofitting.
One of those buildings is owned by Scott Kim and his family. When they bought the five-story factory for their sewing supply business, Kim said, they didn't think to have it examined by a structural engineer.
"It went through other earthquakes, and it's still here," said Kim, whose family paid $5 million for the property a decade ago. "I know back in the day they built buildings much sturdier than buildings today."
Charles Tan, an engineer who has helped retrofit downtown buildings, warned that surviving past earthquakes doesn't mean the structure is safe.
"I've had that said to me quite often: 'Look, this building looks good, has no cracks, no damage,' " Tan said. "A lot of these buildings haven't, at least these specific ones in downtown haven't been tested yet with a high-magnitude earthquake in this exact vicinity."
Owners might be unaware of the risks, but city officials have been warned repeatedly about the dangers of concrete buildings since 1971.
That year, the Sylmar earthquake shattered two concrete structures at the 50-year-old Veterans Administration Hospital in San Fernando. The three-story buildings pancaked when the concrete crumbled, leaving the red tile roof smashed on the ground. Many patients were crushed under the debris; 49 people died.
Seismic experts were more alarmed by Olive View Medical Center in Sylmar, which had opened just months before and was built using stricter codes. The five-story hospital lurched sideways when some of its first-floor columns broke. Three concrete stairwells toppled. A two-story psychiatric building collapsed. Three people died.
After Sylmar, L.A. officials beefed up seismic codes for new buildings, requiring more steel inside concrete columns to prevent chunks from breaking away. The extra steel acts like a cage, keeping the concrete in place, even if the column cracks. But structures built before the mid-1970s remained at risk because many lack adequate steel rebar and can't bend. Engineers call these buildings "non-ductile."
When more concrete buildings fell in the 1994 Northridge earthquake, Los Angeles Councilman Hal Bernson and Karl Deppe, a top city building official, decided the time was right to push for tougher retrofitting laws.
Their proposal called for creating a list of all vulnerable buildings across the city, including concrete ones. Property owners would be required to prepare a plan to strengthen them.
"It would be criminal" not to pursue mandatory retrofitting, Deppe said at the time.
Bernson and others had reason to hope. They had successfully pushed the city a decade earlier to require property owners to retrofit or demolish about 8,000 brick buildings. But Los Angeles was still recovering from a recession after the Northridge quake, and then-Mayor Richard Riordan didn't want to burden businesses with more regulations. Bernson's proposal eventually died. Officials instead settled on a voluntary retrofitting program.
"There's two sides: There's the human risk. There's the financial risk," Bernson said in a recent interview. "To me, there was never any question about the two. The question of human life was always more important than financial."
In the early 2000s, retired building officials tried again to make City Hall focus on concrete dangers. Nothing happened.
Greig Smith, Bernson's former chief of staff, tried twice to revive the issue after he was elected to the City Council in 2003. Both attempts failed. He proposed an alternative: Identify concrete buildings and label the hazardous ones. That failed too.
Property owners have been the biggest opponent of retrofitting rules. Even posting warning signs "scared the heck out of" them, Smith said in an interview.
Many owners say they shouldn't have to pay for expensive fixes on their own.
"The cost of doing this would be greater than the value of the building, and that didn't make sense to us," said Carol Schatz, president and chief executive of the Central City Association.
Researchers who study how concrete buildings fare in earthquakes say 5 percent of these structures typically collapse. In Los Angeles, that would be at least 50 buildings.
Many more need retrofitting. Nabih Youssef, an engineer who helped strengthen City Hall, the Coliseum and other prominent L.A. structures, said that based on his experience, about 30 percent of older concrete buildings require major work. Others believe the number is much higher.
To determine whether a building needs retrofitting, owners would have to spend as much as $100,000 on a structural study that ascertains what is inside the columns.
They would have to hire engineers who might install angled steel beams to provide more support, like an exoskeleton. Another solution could be the addition of sturdy interior concrete walls that stretch from the ground to the roof. The fixes could cost $1 million or more. Occupants probably would have to move out during the renovation, at an additional cost.
"Will it be better safety-wise if you reinforce this? Will you help save lives? Yes," said Martha Cox-Nitikman of the Building Owners and Managers Association of Greater Los Angeles. "But that's easy to say _ if you have money."
(Los Angeles Times staff writer Scott Gold contributed to this report.)
(c)2013 Los Angeles Times
