In the manslaughter trial against master rigger William Rapetti, video evidence showed that the same brand of slings that prosecutors say snapped within seconds when a New York City tower crane collapse on Mar. 15, 2008 held up for several minutes in laboratory recreations by Lehigh University.

The footage was presented during the testimony of Frank Stokes, the manager of Lehigh’s Structural Testing Laboratory, who was trusted by the Occupational Safety and Health Administration to administer the tests.

The prosecution has maintained that the crane fell during the "jumping,” or extension, operation because Rapetti had attached a six-ton collar to the crane’s mast with sun-damaged, frayed and badly configured nylon slings, thus making him guilty of multiple charges of manslaughter, assault, reckless endangerment.
But the straps in the video fared much better than previous testimony would have predicted.

Eyewitnesses John Gallego and John Della Porta have testified about hearing several loud “snaps” and “pops” in rapid succession before the 200-ft-tall crane plummeted to the ground within seconds of the start of the jumping operation and the prosecution’s expert witness Lawrence Shapiro, author of the industry standard guidebook “Cranes and Derricks,” said the entire process would have taken “no more than a couple of seconds.”

Yet multiple videos of laboratory tests showed that, when similar slings were choked in comparable positions around sharp corners on a replica crane mast, full minutes passed between the first snap and the last.

Originally recorded on Aug. 17 to 18, 2008, the video submitted by the prosecution showed the last sling broke “over two minutes” after the first failure, and Stokes admitted under questioning that he heard more than ten popping sounds as the slings shifted, frayed and finally broke.

Eyewitnesses have testified to hearing four loud pops.

Toward the end of the video, an unidentified voice spoke off-camera, “If it took this long for the slings to break, the guys could have gotten off the crane.”

Rapetti’s defense team has, throughout the prosecution’s case, continued to dispute the theory that the slings were the cause of the accident, which left seven dead.

- Adam Klasfeld