THE SIERRA MADRE EARTHQUAKE : Chimneys Fell Like a Ton of Bricks in Towns Across Foothills

One crashed through a red tile roof, lodging in one piece on a huge, exposed beam in the living room ceiling. Another fell--kerplunk!--onto a neighbor’s car. Many others tumbled to earth and became instant rubble.

The chimney--that venerable symbol of hearth and home--was the most easily identifiable architectural victim of the June 28 Sierra Madre earthquake.

All, it seems, were vulnerable: Tall or short. Brick or river stone. Encased in stucco or in rock veneer. Decades old or nearly brand new.

Jolted from footings and stripped away from sides of houses, chimneys crumbled gradually, snapped quickly, toppled slowly, collapsed day by day or just plain fell apart.

Their skeletons these days remain exposed or wrapped in plastic sheeting and tarpaulins on street after street in Altadena, Arcadia, Monrovia, Pasadena, San Marino, Sierra Madre and surrounding areas.

Alongside curbs and gutters, the disembodied--with the best parts culled out in many cases and set aside to live again--wait to be carried away while homeowners puzzle over what happened, how to prevent it next time and how much it will cost to repair the damage.

The official casualty count exceeds 1,900 in six communities. Altadena has recorded 500 damaged chimneys; Arcadia, 322; Monrovia, 354; Pasadena, 533; San Marino, 20, and Sierra Madre, 229.

And, building officials say, that number could grow by 10% to 15% as homeowners discover previously unseen damage during post-quake inspections.

The engineering science of why chimneys are vulnerable is fairly simple, said Pasadena’s Ed Sylvis, who runs a seismic safety construction company.

He explained it this way: “The chimney says to the house: ‘Get out of my way.’ The house says to the chimney: ‘Get out of my way.’ ”

The house, he said, generally wins and the chimney reacts like a poor loser, with a crash and a thud. Or, in case of a tie, the chimney may sulk nevertheless and just pull away a few inches.

In some respects, building officials and masonry contractors say, it is not much of a mystery why a chimney is easy prey. A one-story chimney averages 15 feet in height, and traditional ones can weigh as much as 500 pounds a vertical foot.

Compared to a heavy chimney, a house can be as flexible as a wooden ship in wind-battered seas.

But in most cases, said Paul Sheedy, Monrovia’s head building official and a civil engineer, “a properly constructed, modern chimney wouldn’t have any problems in the quake we had. We can build chimneys that don’t fall down, if we do it right.”

After the 1971 Sylmar quake, Sheedy said, construction standards were upgraded. Decades ago, chimneys were not reinforced. They were simply a brick or stone box with a big opening at the bottom.

Today, when chimneys are built, two quake safety elements are incorporated: steel rods that run the length of the chimney, and metal strips that bind the chimney to the roof or ceiling joists.

Also, to solve the weight problem, Sheedy said, lighter-weight, prefabricated chimney boxes with metal flues and surrounded by a veneer are routinely built.

Still, building officials and contractors said the key issue, whether a chimney is new or old, revolves around workmanship.

Decades ago, to cut corners, masons would use lime instead of quality sand as a filler in mortar, said Robert Castellano, a senior building inspector in Monrovia. The lime disintegrates much quicker. Likewise today, he said, shortcuts are sometimes taken and result in costly repairs.

Thus the business of chimneys can become quite serious to the homeowner. To repair just from the roof line up can cost an average of between $2,500 to $3,000. More extensive work, such as replacing a full chimney, can run $12,000 to $15,000.

The most expensive time to repair, Sylvis said, is right after a quake. During the same period, he added, irresponsible contractors sometimes are looking for quick money from easy victims. He said the most prudent course for a homeowner, after initially taking the necessary safety precautions to remove damaged parts of a chimney, is to delay somewhat before undertaking the full repair job.

No matter when repairs are done, the cost can vary widely, according to William Schlecht, the top building official in Pasadena. “It’s like saying: ‘What does a car cost?’ It’s different if you want a GEO Storm or a Maserati.”

Some people wonder, if modern engineers and architects can design skyscrapers that sway with earthquakes, why not chimneys?

The answer, Schlecht said, is cost: a chimney based on a similar high-tech solution would be prohibitively expensive. Anyway, he said, the lightweight, prefab chimneys usually can provide the same safety.

Yet as Castellano cruised along Monrovia’s streets Tuesday, he saw toppled every kind of chimney imaginable. With each quake, he said, there always remains one mystery for him.

“You’ll have two houses side by side,” he said, pointing to a perfect example of the scenario. “We will lose one chimney and not lose the other. I’d love to X-ray that good one, or to take it down, to see why it’s still standing.”