The garage collapse that killed four construction workers and injured 20 others last October during a $245 million expansion of the Tropicana Casino and Resort was caused by the faulty installation of concrete floors after changes were made to the design to speed the job and save money, according to engineers for the contractors and others who have studied the design plans and the debris.
The way prefabricated steel reinforcement rods and an underlying beam in the garage floors were connected to six critical outer vertical columns, as part of the way the revised design was executed, resulted in a building that engineers now say was all but destined to collapse.
Whether it was a flaw in the way the structural plan was revised or simply sloppy execution of the revised plan is in dispute. But at least four engineers who have examined the debris collected from the collapse site — including the engineer who originally designed the garage — said it was clear that crucial steel connections were lacking, making it impossible to support the enormous weight of the concrete floors of the 10-story, 2,700-space garage after the revised design was executed.
“It was supposed to save time and money,” said Stephen V. DeSimone, president of DeSimone Consulting Engineers of Manhattan, the structural engineer on the complex, who said he believed that the problem occurred in the execution of the revised design, not the design itself. “Four men went to work that day expecting fully to come home. For it to have gone so wrong, with such significant consequences, it troubles me. It rocks my confidence in the industry.” The engineers also generally suspect, as laborers at the work site had warned for weeks before the collapse, that there was not sufficient shoring of the concrete floors that had just been poured, something essential, for the floors must harden before they reach their designed strength.
Federal investigators will soon release their own analysis of what happened on Oct. 30, a block from the famed boardwalk, when the floors of the garage suddenly opened up like trap doors, sending scores of workers tumbling to the ground.
Officials at the United States Occupational Safety and Health Administration, which is conducting the investigation, declined to comment.
But the engineers and other contractors, whose files have been subpoenaed and employees deposed, said they believed the investigators would also cite the connection between the concrete floors and the outer columns as the collapse’s primary cause.
“There is no visual evidence of the expected reinforcement between the slab and the columns,” said W. Gene Corley, a structural engineer from Illinois who led the federal investigations into the collapses of the Alfred P. Murrah Federal Building in Oklahoma City and the World Trade Center and is now an expert representing victims of the Atlantic City collapse.
Officials at Fabi Construction Company of Egg Harbor Township, N.J., which was in charge of building the concrete floors, would not comment on the cause of the collapse. Representatives of Keating Building Corporation of Philadelphia, the general contractor, and Aztar Corporation, the Phoenix-based casino company that owns Tropicana, said they could not discuss the details, given the pending lawsuits and investigations. “Every decision made was intended to deliver the highest quality product possible,” Keating said in a written statement.
But the findings are sure to infuriate the families of those killed or injured, and complicate the legal challenges for the companies involved in the construction project.
“Someone should be held criminally responsible,” said Robert A. Tartaglio Sr., who worked on the Tropicana expansion last year with his son, Robert Jr. — one of the four men killed in the collapse. “Someone is responsible up the line for making these decisions. And as far as I am concerned, they committed a crime.”
On Thursday, Jeffrey S. Blitz, the Atlantic County prosecutor, confirmed that a criminal inquiry was under way. “This office is gathering data,” he said. “When we receive all the available information, we will decide.”
The Tropicana Casino and Resort expansion had been promoted as an impetus for a revival of the Atlantic City economy, including not only an expanded casino, but also an entertainment, restaurant and retail complex that is supposed to turn this beach-side resort into a more Las Vegas-like draw. The 10-story garage — eight stories of which are parking — is only the footnote of a project that also includes a new 31-story hotel and 220,000 square feet worth of restaurants, stores and live music venues, in a Havana-inspired complex that is to be called The Quarter.
Keating Building, in the statement it issued in response to questions, said that the project was on time and on budget, disputing the assertion by Mr. DeSimone that the design was changed, after the state had approved the original engineering plans, to cut the cost and possibly accelerate the construction. But Fabi officials have said that the project had a late start because of a particularly snowy winter in Atlantic City in late 2002 and early 2003.
Initially, in the lower floors, ironworkers were individually threading reinforcing steel, known as rebar, from the concrete floor slab of the garage into the six vertical columns at the edge of the garage.
But the contractors — it remains unclear if it was both Fabi, the concrete firm, and Keating, the general contractor, or just one of them — had asked DeSimone Consulting Engineers to consider an alternative. At the outer wall of the garage that would be redesigned, factory-made, eight-foot-wide cagelike mats of rebar would be used, instead of individual rods of rebar. At an earlier stage, the plan for how to build a critical support beam underneath this area was also revised, making the beams shallower and wider.
Mr. DeSimone said he was convinced that the alternative structural design his firm had approved — at the contractor’s request — was sound. The problem, he said, may have been in the translation of the revised structural design into the drawings used by contractors in the field. Also, in the construction the rebar mats were not placed far enough into the columns so that they would be anchored with the vertical rebar, ensuring a solid grip. That may be because the rebar mats were harder to handle, or just did not fit. Whatever the reason, the problem appears to have occurred on almost all of the upper floors.
Another person who has examined the plans said that the revisions themselves were most likely flawed: a support beam intended to shift the weight of the floors onto the columns was moved, and the columns themselves were made smaller. Both changes significantly weakened the structure, according to the representative of one of the contractors. Mr. DeSimone said he was confident this conclusion would be proved wrong.
The Occupational Health and Safety Administration, whose investigation into the accident, by law, must be released by April 30, will most likely address these and other questions, and also focus on the adequacy of the site supervision by the contractors and a company hired to inspect the work, Site Blauvelt of Mount Laurel, N.J.
What remains unclear to all the engineers involved is how the construction could have moved ahead with such obvious flaws, regardless of whether they had been based on a troubled design or just poor execution of the revised design.
“Everywhere along the line, the checks and balances failed,” said an engineer for one of the contractors, who asked that he not be named because of the ongoing investigation.
The laborers and carpenters at the site, in interviews, said they did raise objections about a condition they thought was hazardous: the insufficient shoring that was being used to hold up the not-yet-dry concrete floors. Workers said they noticed that some of the shores — essentially temporary steel or wooden pogo sticks that go from the ceiling to the floor — were under such stress that they were bending or bowing. Laborers also reported troublesome-looking cracks in the concrete. But George Tolson, one of the Fabi laborers who noticed this condition, said he was told to keep working.
“All they wanted,” said David R. Hand, 33, a laborer for Fabi who was pouring the concrete “is to go faster, faster, faster. Time is money. That was it.”
When the collapse started at about 10:40 a.m., Mr. Hand was on the top floor of the garage, parking level 8, using a large crane-mounted hose to pour an area of concrete more than 60 feet wide. This is the moment of most intense stress, as the wet concrete, which weighs 160 pounds per square foot of floor, cannot support itself.
Mr. Hand felt a vibration, which in itself is not uncommon, as the concrete settled. But it continued for about 10 seconds. Then, suddenly, the floor below him opened up. Mr. Hand essentially surfed his way down to what he assumed would be his death.
“The piece I was standing on, I watched it fall and then hit the bottom and smash into pieces,” he said, during an interview at his lawyer’s office.
Mr. Hand, after grabbing some of the collapsed rebar mat to climb out of the debris, emerged with a slash in his head, a detached eyelid and several fractures. Five floors on one end of the garage had pancaked — beginning at just the spot where the rebar mat and the revised beam had been used — although the rest of the garage remained standing.
“Every day now, I ask myself, why did God spare me? Why was I able to walk away? What was the big reason?” he said, adding that while his health continues to improve, he still has nightmares and doubts he could ever work in a tall building again.
Mr. Tartaglio looks each day at the green hard hat, tools and lunch box once used by his son — they were not recovered until last month — wondering just the opposite: why so many others lived, when his son, a father of two school-age daughters, died.
Lawyers representing Mr. Hand and Mr. Tartaglio and other workers said previous accidents involving Fabi and Keating at the same Tropicana casino complex should have been enough to ensure that extra special safety precautions were being taken.
In June 1995, a 23-year-old Fabi worker who was removing concrete slabs atop Tropicana’s adjacent 10-story parking garage fell 100 feet to his death, down an elevator shaft, after the floor he was standing on collapsed. Fabi was fined $31,500 by the federal government and Keating was fined $6,400, after authorities concluded that the workers had not been properly trained or supervised.
Then, in October 2002, after work on the new expansion got under way, three workers were injured when the concrete floor they were standing on gave way and they fell to the ground. In this case, according to one contractor, there was no shoring at all underneath the area where the men were working. Keating was in this case fined $1,125 and Fabi $8,375, although the penalties are being appealed.
Jim Moran, director of the Philadelphia Area Project on Occupational Safety and Health, a union-backed group representing about 100,000 workers, said all workplace deaths were horrendous. “But it is even more egregious,” he said, “when it is a repeat offender. If you are going to keep fining people for killing other people, on its face, that is ridiculous.”
Lawsuits have been filed by the injured workers and families of those killed last year.
Even while the OSHA investigation continues, work has started again on the unfinished parts of the Tropicana hotel and garage expansion. Keating and Fabi workers, along with other contractors, are back at the site, working to finish the complex, which was to open this spring. The collapsed floors of the garage are being removed one tiny chunk at a time to try to prevent the rest of the structure from collapsing.
The contractors, meanwhile, have decided to return to a design that is very much like the original as they start rebuilding the collapsed garage.