The report says that an investigation by Arup & Partners Consulting Engineers found that DOB crane inspection and permitting protocols would not have identified the rigging errors that caused the collapse at 303 E. 51st St. Those errors included the use of four synthetic slings instead of the eight chain blocks specified by the manufacturer to support an 11,279-lb. steel collar, prior physical damage on one of the slings, improper attachment of the slings and a lack of padding for the slings.

Arup's investigation concluded that the tower crane installation design met industry standards and was not a cause of the crane collapse, which occurred after the crew had "jumped" the crane, or extended its height. "The collapse of the tower was initiated when the polyester web slings supporting a steel collar at the 18th floor level failed, allowing the collar to fall," according to the DOB report.

A stop work order remains in effect at the construction site. The project to construct a 43-story apartment tower had its building permit revoked after the March 15, '08 crane collapse, which killed six construction workers and one civilian, demolished a nearby brownstone and damaged more than a dozen buildings.

In a statement, LiMandri says crane assembly is "a highly technical activity that requires great skill and adherence to the crane manufacturer's instructions. Deviation from those instructions can have catastrophic results. This investigation shows the consequences of taking shortcuts on the job site." He adds that DOB will convene a series of meetings with the construction industry "to review the report's findings and identify ways to prevent tragedies like this from happening again."

Crane Collapse

Earlier that month, Manhattan district attorney Robert Morgenthau filed charges against the crane rigger and his company. The indictment against William Rapetti and Rapetti Rigging Services includes multiple charges of manslaughter, criminally negligent homicide, assault, reckless endangerment and failure to file tax returns. Rapetti's attorney, Arthur Aidala of Aidala & Bertuna, told GlobeSt.com in January that his client was "determined to help clear his name and demonstrate that he and his company operated and supervised the site in a manner beyond reproach."

In recent weeks, DOB inspectors performed inspections of all tower cranes undergoing jumps. The inspectors found that all 18 were in compliance with new crane safety laws enacted since the March '08 collapse, according to a release.