Degenkolb Engineers designed the structural system for the Ocosta Elementary School and tsunami vertical evacuation refuge. The evacuation structure is the first of it’s kind in the US. The roof of the school gymnasium is a designated safe refuge and it has a capacity for over 1,000 people. Performance-based design methodologies were implemented to ensure that the structure would be able to resist a Cascadia earthquake while having sufficient capacity to resist subsequent tsunami inundation forces. Degenkolb worked closely with the University of Washington-based inundation modeling team to develop key design parameters, resulting in a safe refuge which is 55 feet above sea level and 28 feet above grade. The building features reinforced concrete stair towers and concrete-encased columns to protect against impact forces, drilled piles to resist scouring and liquefaction, and contains measures to prevent progressive collapse due to extreme impact loads.