Bus and school bus structures are often at issue in collisions. ARCCA was asked to investigate the crashworthiness of a school bus window that popped out from the frame during an accident, and a child was ejected from the bus and killed. An ARCCA crashworthiness engineer demonstrated the defect on an exemplar side structure and window. Additionally, he designed, developed, and tested an alternative design for this highly critical safety component. Our engineer proved the window structure failure was of proximate cause to the injuries, and that a reasonable alternative design was available that would have prevented the injury.