Forensic engineering 

Abstract: In the early morning hours of May 16, 1968, the occupant of apartment 90 on the 18 th floor of the Ronan Point apartment tower lit a match to brew her morning cup of tea. The resulting gas explosion initiated a partial collapse of the structure that killed four people and injured seventeen. On investigation, the apartment tower was found to be deeply flawed in both design and construction. The existing building codes were found to be inadequate for ensuring the safety and integrity of high-rise precast concrete apartment buildings. The Larsen-Nielson building system, intended for buildings with only six stories, had been extended past the point of safety. The tower consisted of precast panels joined together without a structural frame. The apartment tower lacked alternate load paths to redistribute forces in the event of a partial collapse. When to structure was dismantled, investigators found appallingly poor workmanship of the critical connections between the panels.

Abstract: The Teton Dam in Idaho failed on June 5, 1976, flooding towns and farmland downstream. Fourteen people were killed and property damage estimates ranged from 400 million to one billion dollars. The failure occurred during the initial filling of the reservoir. An independent review panel convened by the Governor of Idaho and the Secretary of the Interior found that the most probable cause was piping of the dam fill material. The fill material was highly erodible fine wind-blown silt. Excavation of the failed dam under the supervision of the review panel found that the grout curtain had gaps or windows, and the underlying rhyolite formation had fractures and joints that could have allowed enough water to pass to initiate the piping. The weak materials were identified before construction. The lessons learned from this case led to safety improvements for U.S. Bureau of Reclamation design procedures.