From a distance, the Watts Towers rise as a beacon of pride in a community that has struggled for years with poverty and crime.
But up close, tiny cracks are tearing through the historic sculpture. One particularly nasty fissure starts thin at the base of the 99-foot center tower, then widens and snakes over colorful tiles, branching like a network of veins from an artery. Decorative ornaments — pieces of glass, seashells and pottery that artist Simon Rodia painstakingly affixed — are falling off, bit by bit.
The towers have been deteriorating for years, prompting quick patch jobs that did little long-term good. A worker with binoculars would spot a crack, panic and rush to seal it over with cement and other materials. But the cracks always came back.
Now, a team of engineers and conservationists have descended on Watts to try to discover the root problems for the decay and come up with a more lasting fix.
Frank Preusser, conservation scientist for the Los Angeles County Museum of Art, has hooked the towers up to several devices to monitor its complex condition. Three sensors track movements of the cracks, measuring wind gusts and minute vibrations.
UCLA engineer Robert Nigbor said he's approaching the problem like a doctor in search of a diagnosis: "Is it the wind? Is it the sun heating the structure? Is it temperature or earthquakes that are the main cause of the cracks?"
Concerned about the towers' frail state, Los Angeles' Department of Cultural Affairs contracted with LACMA in 2011 to help with maintenance and restoration.
"For 50 years, the committee has been trying to get to this point," said Janine Watkins, a member of the group that has fought for decades to keep the towers.
Using funds raised by LACMA, Preusser and four full-time museum employees keep daily tabs on the towers. In December, UCLA engineers joined the effort to perform structural tests.
So far they've spent $2 million but say much more will be needed to stabilize the landmark.
On a recent day, LACMA employee Sylvia Schweri-Dorsh stabilized a wobbly column that had separated from the foundation. Another employee, Blanka Kielb, patched a gaping hole with mortar.
Nigbor checked on a newly installed wind sensor — painted blue to conceal it against the sky — that measures how wind gusts affect the vibration of the structures.
Data collected so far point to a monument that mimics a living organism: cracks contract and expand as if the tower is breathing. And the structures tilt to the north when the sun rises and return to their original position when the sun sets.
It's this flexibility that helped the towers survive the 1994 Northridge earthquake, engineers said, but the constant movement is also why past restoration efforts were short-lived.
"My diagnosis of the past failures is that they repaired the cracks with a very rigid material," Preusser said. "And they used five or six materials, but they were all rigid because they were only thinking about corrosion."
Heat causes the cracks to open and close, but the fissures never return to their original size, Preusser said. Debris gets lodged inside, and the cracks get longer.
The team is slowly getting closer to determining the best way to repair the cracks and reattach artifacts after testing dozens of mortars, crack fillers, adhesives and water repellents.
Besides the towers' daily movement, Mother Nature is also contributing to the slow deterioration. A 2003 hailstorm brought down glass, seashells and tile ornaments. But Preusser's team is finding that howling winds are causing the most damage.
"A Santa Ana wind produces about the same force as a moderate earthquake on the structure," Nigbor said, adding that he hopes planting tall cypress trees may serve as a windbreak.
Still, two years into what was slated as a yearlong project, the team is more certain than ever about one thing: The towers will not topple, a long-standing fear.
Rodia, a construction worker without any art training, spent his free time over 33 years building the installation in his backyard without the city's approval. He completed the 17 interconnecting sculptures adorned with intricate mosaics in 1954.
Several years later, when officials learned of the hidden gem 13 miles south of downtown, they immediately issued a demolition order, worried that it posed a safety hazard.
"Personally, I think this is the biggest pile of junk outside a junkyard that I have ever seen," the head of the municipal Building and Safety Department wrote in a memo at the time.
To prove that the monument was structurally sound, engineers attached a big truck to the tallest tower. It stood firm against 10,000 pounds of force.
Five decades later, Preusser's tests confirmed that the towers are sound.
"The biggest risk here is not that the towers will fall over, keel over," he said. "The biggest risks are of big chunks coming down" and injuring visitors.
As the team gets closer to solutions, others in the folk art world are taking note.
"We are possibly breaking ground here," said Preusser, whose portfolio includes work on the Sphinx and the tomb of Egyptian Queen Nefertiti. "There are a number of similar structures, but not that tall. They all pose the same problems, and interestingly enough, all of them are looking at us now."
In Philadelphia, Magic Gardens, an outside art labyrinth of mosaics completed five years ago, is already cracking and losing decorations. So is the Nek Chand Rock Garden in India.
The findings from restoring the Watts Towers may help with future preservation projects — but coming to the right conclusions will take additional time, Preusser said.
He ignores impatient critics who just want the cracks filled.
"I got email after email. 'Why haven't you started filling cracks?'" Preusser said. 'And I reply, 'Do you want me to fill cracks the same way knowing it will fail?' …. I want to make my own mistakes and not repeat the mistakes of the past."