Philadelphia Building Collapse during Demolition

A four story building in Philadelphia, PA, collapsed in 2013, onto an adjacent occupied building, killing six persons and injuring over a dozen more. The building was in the process of being demolished. The author’s firm was retained by attorneys to investigate the causes of the collapse, to determine the roles and responsibilities of the various parties, and to determine whether the demolition process was performed in accordance with industry standards. Thus, as part of the investigation, we inspected the debris, we reviewed all available project documentation and standards of practice, and we collected photographs and videos of the demolition process from social media and other sources. This investigation enabled us to reconstruct the demolition sequence that was actually used, and the status of the demolition moments before the collapse. Therefore, the author testified in criminal court on behalf of the City of Philadelphia. The focus of the testimony was on contrasting the demolition sequence that was used to the sequence that should have been used. To clearly communicate this to the jury, a 3D digital model was developed, which was used to show the jury what the building looked like, from any angle, just before the collapse. An animation was also developed, to show the proper demolition sequence. Furthermore, this paper presents the findings of the investigation, discusses expert testimony, and provides recommendations for minimizing similar failures in the future.