April 2, 2002|
U.S. Report on Trade Center Echoes Lessons of Past Disasters
By ERIC LIPTON and JAMES GLANZ
A New York City skyscraper burns out of control, fireproofing is absent or fails, structural steel warps and snaps, floors begin to collapse, workers in the building die.
The date is Aug. 5, 1970. The skyscraper is called 1 New York Plaza, less than a mile from where the World Trade Center towers were rising into the clouds.
The fire and collapse of the World Trade Center last Sept. 11 in many ways stand alone, both in the terrifying attack and in the incomprehensible death toll. The first federal assessment of the trade center disaster, which The New York Times obtained last week, has made clear that there may have been no reasonable precautions that could have stopped the towers from collapsing once they were struck and huge fires broke out.
But in the same report, parallels between the demise of the twin towers and deadly fires in other high-rises in the United States since 1970 are disturbingly apparent and at times, explicitly drawn.
After the 1 New York Plaza fire, federal investigators cited flaws in light fireproofing sprayed onto steel structural supports that had fallen off or flaked away, leaving beams vulnerable to failure and collapse in the superintense heat. After a fire at the First Interstate Bank in Los Angeles in 1988, the same federal agency warned that radios did not work properly in steel-frame skyscrapers.
And a huge high-rise fire in Philadelphia in 1991 led federal experts to conclude that tests for assessing structural integrity in fires, dating back to the early 20th century, were technically primitive and unreliable for the high-temperature blazes in offices filled with plastic computers and synthetic furniture.
The assessment of the trade center collapse, by the Federal Emergency Management Agency and the American Society of Civil Engineers, does not draw conclusions about whether even the best-designed fire suppression system could have saved the buildings. The report also credits the structural design of the towers for surviving the initial impact. But it cites the same hazards identified by federal authorities in the earlier fires as contributing to the death and destruction on Sept. 11.
"Spray-applied fireproofing may be vulnerable to damage from blasts and impacts," says a draft of the FEMA report, adding that failure of support structures protected with this fireproofing "is likely critical to the ultimate building failure."
A New York City inquiry has already revealed that emergency personnel in the trade center on Sept. 11 were at times unable to communicate because of radio problems, and the FEMA report says that the nation's standard fire test "does not reflect the behavior of floor and roof constructions that are exposed to uncontrolled fire in real buildings."
These echoes show that while the trade center demise was like no other disaster, the reports on the earlier fires warned that the same dangers could cost many lives.
"It fits, obviously, on the extreme end of the spectrum, because this is the worst building disaster we've had, ever," said Donald Bliss, vice president of the National Association of State Fire Marshals. But he added, "Are there indeed the proper fire protection systems and capabilities in place to react to a catastrophic fire, irregardless of the cause?"
It's a question that firefighters, in New York City at least, had been asking long before Sept. 11, and they see in that disaster a horrible validation of their long apprehensions about the dangers of fighting major fires and performing evacuations in modern, lightweight high-rises.
"With the old buildings, you know the building's going to hold," said Neil P. Winberry, a retired New York fire captain. "You've got time to work." After the city fire code was changed in 1968, allowing a widespread shift from masonry fireproofing to a light, spray-on product, Mr. Winberry said, "we could not understand how this was going to work; we had no faith in it."
Over the past century, calls for reform in the byzantine world of fire protection and building standards have far exceeded substantive changes. Yet there are already signs that the calls for change may be heard this time.
In New York City, a post-Sept. 11 task force began meeting last month to examine the adequacy of city codes and regulations on fire protection, structural integrity of buildings and emergency exits.
David A. Lucht, director of the Center for Fire Safety Studies at Worcester Polytechnic Institute, said economic pressures along with the effectiveness of sprinkler systems for smaller fires had actually led to a weakening of standards for fireproofing that is applied as insulation to structural steel.
"The trend towards cutting back" on such fireproofing has been there for several decades, Professor Lucht said, describing the combination of steel insulation and sprinklers as "belt and suspenders."
High-rise disasters are rare. But the particular vulnerabilities identified at the trade center and in other high-rise fires might force modifications that could greatly reduce catastrophes, perhaps even in terrorist attacks. Conclusions drawn from extensive data gathered from damaged or destroyed buildings around the twin towers — structures that caught fire but were not hit by an airplane — are reinforcing the case for changes.
"It may be decided that we need to go back and heavy up the belt and heavy up the suspenders," Professor Lucht said.
The most frightful confirmation of that view might be seen from inside a burning tower. Shortly before 6 p.m. on Aug. 5, 1970, an elevator carrying two security guards and a telephone technician opened unexpectedly on the 33rd floor of 1 New York Plaza, a 50-story skyscraper so new that some tenants were still moving in. The elevator had been called to the floor by one of the old-style buttons that lighted up from the touch of a warm finger. Flames and smoke rushed into the elevator and forced the men to the floor.
Two died before rescuers could arrive. The fire rushed up ventilation shafts from the 33rd floor, where it melted the metallic bases of typists' chairs, reaching the 35th floor. Light, spray-on fireproofing, which at some point had been knocked away, left steel supports for the floors exposed to the blaze. They twisted and pulled away from their connections, initiating collapses that stopped only because the concrete slabs of the floors refused to give way.
Although the building stood, the fire burned for more than six hours. The heat-activated elevator call buttons were phased out after the investigative report cited their dangers, but not all of its warnings were heeded. "The protection of steel members in a really fire-resistive building must be accomplished by materials that cannot be readily removed or damaged," the report said in a harbinger of language that has reappeared in the trade center draft, even though the formula for the twin towers spray-on fireproofing was somewhat different.
"It is apparent that sprayed fiber may not be universally applied to the proper thickness, that proper adhesion to steel may not take place and that the protection may be removed in many locations," the report on the 1970 fire said.
A 1988 high-rise fire in Los Angeles sounded another prescient alarm. Flames from the blaze at the 62-story First Interstate Bank building, then the tallest tower west of the Sears Tower in Chicago, lapped up the side of the building, gutting offices from the 12th to the 16th floor.
By all accounts, the response was fast and well organized, as firefighters quickly eliminated a water-supply problem by linking mobile pumpers into the building's system. But radios did not transmit clear signals because of the skyscraper's steel frame. And with so many firefighters responding, the radio system was overwhelmed.
At the height of the blaze, a firefighter had to smash open a 10th-floor window to communicate with a commander at the street level. The fire burned for three and a half hours, killing a maintenance worker and injuring 35 others.
Engineers later discovered that the building survived the fire with surprisingly limited structural damage; credit was given to especially thick layers of a relatively heavy, cementlike fireproofing that had been applied to structural steel. The World Trade Center had the much lighter, easily dislodged fireproofing on the floor braces whose failure probably initiated the collapse.
And despite the warning on radios in high-rises, the problems still were not completely solved, at least in New York: radio transmissions were spotty in the twin towers, and an order to evacuate the towers before they collapsed was not received by many firefighters.
No modern fire strikes as strong a resonance with the trade center as the 19-hour, eight-floor fire at 1 Meridian Plaza in Philadelphia. Three firefighters died, few compared with the 343 firefighters who died at the World Trade Center. But just as on Sept. 11, multiple fire protection systems failed, were overwhelmed or were simply knocked out of service.
"Perhaps the most striking lesson to be learned from the 1 Meridian Plaza high-rise fire is what can happen when everything goes wrong," said the FEMA report on the fire.
The water supply was inadequate; although the building remained standing, huge floor beams heated and sagged as much as 36 inches, despite their fireproofing; sprinklers and smoke detectors were sporadic at best; electrical power was lost and the building was plunged into darkness.