Questions About Wind as Dallas Crane Mishap Claims a Life
A stormy Sunday afternoon in Dallas with gusts of 70 mph or higher. A tower crane tied to a new apartment building frame tumbles, smashing a completed parking structure behind it. Other sections rip through a completed apartment building, killing 29-year-old Kiersten Symone Smith.
A bad year for crane accidents became worse June 9. On April 27, a tower-crane failure killed two ironworkers and two passersby in Seattle. That accident still is being investigated with a focus on dismantling procedures.
The latest accident is likely to focus more attention on tower-crane wind resilience. Crane experts and investigators interviewed by media outlets talked about the importance of leaving tower cranes unbraked and free to weathervane in high winds. In October 2018, federal investigators from the Occupational Safety and Health Administration reported that SK-315 hammerhead cranes whose jibs came down during Hurricane Irma in Miami likely failed due to turbulent wind imposing violent upward and lateral forces on the jibs.
Exactly what model of tower crane fell in Dallas, and what wind loads it was subject to, are unclear. An attorney for Bigge Crane and Rigging Co., which supplied the crane and its operator to the project as an equipment rental provider, confirmed in a statement that the crane was not being operated when the storm hit. But the San Leandro-based company did not release any additional information about the crane model or its condition. The attorney said that the fallen crane sections, which remained embedded in the partially destroyed building sections and had forced the evacuation of the apartment residents, would remain where they fell until OSHA completed its work at the jobsite.
Greystar, the developer of the new building and the owner of the existing ones, could not be reached for comment on the tragedy or the aftermath for the project team.