TANGLED ISSUE Tropicana garage bay failure killed four workers, but prime cause isn’t clear. (Photo by Richard Korman for ENR)

There were many points left unmade by the federal government’s proposed penalties against the contractors and inspection firm on a casino garage in Atlantic City, N.J., where four workers died in a partial collapse last Oct. 30. The U.S. Occupational Safety and Health Administration blamed improperly made connections and sloppy shoring but did not identify the triggering event. Yet it was impossible to overlook the bluntly worded assessment of the contractors’ performance by one top OSHA official in the agency’s April 29 report.

Area Director Gary Roskoski described the mistakes as "Engineering 101." An attorney representing the family of one dead worker said the accident was "an absolute colossal and systemic failure from top to bottom." But victims’ relatives expressed disgust with the modest proposed fines–a total of $119,000 against four firms. Federal officials say it was the maximum they could propose under current rules.

The exact triggering cause of the Tropicana casino-resort collapse still remains to be identified. Participants and observers say that discussion apparently will await the multimillion-dollar lawsuits expected to be filed soon against the contractors involved (see chart). The companies and their insurers have hired numerous engineering experts to help prepare their legal defenses, according to some of the engineers involved.

Even with the legal complexities, the alleged errors were remarkably simple. Contractors on the project failed to tie rebar in the concrete frame’s floor beams to the columns and shear wall in several places at the end of the garage’s last bay, OSHA claims. It also says that the firms failed to properly shore the structure and that the inspection firm failed to notice that installed reinforcing deviated from the rebar and welded-wire-fabric mesh specified in the design by DeSimone Consulting Engineers, New York City. No penalty was proposed against that firm. Principal Stephen DeSimone calls OSHA’s assessment "a bittersweet vindication" because of the loss of life.

The exact picture of what occurred is still hazy. Neither OSHA nor the firms involved have released design or shop drawings used on the project. The looming lawsuits also prevent most principals from commenting in detail.

The garage project was being constructed with the widely used filigree wideslab method, in which precast forms combine with cast-in-place concrete to create a composite structure. The method saves time and money, say proponents. At one point, the rebar design changed, but OSHA says the missing connections meant the structure was not being built as designed (ENR 11/17/03 p. 14).

Project contractors were hurrying to complete the garage after rainy weather cut into the schedule. They wanted to meet deadlines to open the resort hotel’s newly completed buildings. Roskowski says that worker complaints about cracked concrete in days preceding the accident should have "raised a red flag."

The collapse occurred during concrete placement at the eighth level of the garage’s end section, with five floor slabs collapsing progressively. The floors severed from a shallow shear wall that remained standing but which has since been demolished.

OSHA says Fabi Construction Co., the Egg Harbor Township, N.J., principal subcontractor, and Mitchell Bar Placement Inc., Sewell, N.J., failed to embed welded-wire-fabric mesh and top longitudinal rebar of the exterior beam into six columns along the shear wall in the last garage bay. That deviated from the American Concrete Institute’s standard 318-95 and prevented the connection from developing full strength, OSHA claims.

No shoring plans existed for five floors in the bay and Fabi failed to assure that base plates, shore heads, extension devices and adjustment screws in the shores were in firm contact and secured when needed, OSHA contends. The contractor also...