Inspectors believe last week's floor collapse at the David L. Lawrence Convention Center was a singular event and that the rest of the building is structurally sound, Mayor Luke Ravenstahl said Thursday.
"It appears the collapse that occurred was an isolated incident and the structural integrity of the building is intact and should be fine," Ravenstahl said.
Allegheny County Chief Executive Dan Onorato declined to comment. He and Ravenstahl were expected to be briefed on the inspectors' findings and could release the information as soon as today.
The city-county Sports & Exhibition Authority, which owns the building, hired three companies involved in the building's construction and two independent firms to inspect the Feb. 5 collapse of a second-floor loading dock. A 60-foot steel beam and the concrete floor crashed onto 10th Street and walkways beneath the convention center. No one was injured, but the building has been closed since the collapse.
The three companies involved in the center's construction and the recent inspection are preparing to defend themselves against a lawsuit filed in connection with a fatal truss collapse in 2002.
Dick Corp., the Jefferson Hills subcontractor that raised the building's skeleton, London-based structural engineers Dewhurst Macfarlane and Partners, and prime contractor ADF International of Canada are scheduled to go on trial March 13 before Allegheny County Common Pleas Judge Judith L.A. Friedman.
They are being sued for negligence by New York-based National Union Fire Insurance, which was hired by the sports authority to insure the companies that built the center. The insurer is seeking to recoup more than $1 million it paid after the truss collapse. The lawsuit names a fourth company, Williams Form Engineering, a Michigan supplier of nuts and bolts.
The lawsuit contains a previously undisclosed report by inspectors with the federal Occupational Safety and Health Administration, who faulted Dick Corp. for contributing to the 2002 collapse by using only one crane to support the building when construction plans called for two.
The OSHA report concluded that "structural stability was in question when they released the second crane," according to the lawsuit, which claims an iron worker's inadvertent use of improper nuts was not the only cause of the collapse that killed him.
National Union Fire Insurance claims a key change in the connection that eventually broke on Feb. 12, 2002, toppling a 150-ton truss that crushed iron worker Paul Corsi Jr., was "improperly designed" by engineers and insufficiently explained to the people responsible for building the Downtown convention center.
The lawsuit was filed in 2004 and does not address last week's collapse. ADF International did not return calls for comment. Dick Corp. and Dewhurst Macfarlane declined to comment.
Sports authority Executive Director Mary Conturo declined to comment on the National Union lawsuit, or any others related to the convention center.
In a separate matter pending in Common Pleas Court, ADF -- which supplied steel for the convention center -- sued the sports authority in 2003, alleging construction plans were incomplete and contained errors, leading to costly corrections and modifications.
"Neither (the authority) nor its architects and engineers fully appreciated how the building would react as the structure was constructed, the roof components were installed and the steel cables were tensioned with the resultant forces, pressures and (movements) being transferred throughout the building," ADF states in its lawsuit.
The National Union lawsuit reiterates conclusions of a 2002 coroner's inquest into Corsi's death. Workers used the wrong nuts to hold down the steel structure, and neither their foreman nor his superiors checked the work. Most of the nuts were not screwed down, making the connection even weaker.
A separate testing firm hired by the sports authority was required to check only 10 percent of nut-and-bolt connections, the inquest determined.
But the insurer's lawsuit goes further, detailing how ADF changed the original plans and completely redesigned the connection that failed.
Benjamin Lavon, a New York engineer hired by the insurance company's attorneys, claims ADF's drawings of the redesign were "missing crucial information and specifics" about how to assemble the connection. Lavon says Dewhurst Macfarlane and Dick Corp. "failed to realize that this crucial information was missing" from the drawings.
Dewhurst Macfarlane counters in pretrial papers that another expert, William W. Merrell, of Columbus, Ohio, found that ADF's plans were "sufficiently complete, and compliant with standard practice."
Another analysis done by Ronald J. Cohen, a suburban Philadelphia engineer cited by Dick Corp. and ADF International in their pretrial statement, says Dewhurst Macfarlane should have inspected the "critical connection," and the nut supplier contributed to the problem by failing to tell Dick Corp. it had shipped weaker nuts in place of stronger jam nuts.
National Union's lawsuit blames Williams Form Engineering for shipping a custom-made batch of nuts that ironworkers ended up confusing with the proper nuts.
