Bumper system with energy absorber

A bumper system for an automobile vehicle includes, in an exemplary embodiment, a beam configured to attach to the vehicle, and an energy absorber coupled to the beam. The energy absorber includes a body, an upper crushable member extending from the body, and a lower crushable member extending from the body and spaced apart from the upper crushable member. The upper and lower crushable members each include an upper transverse wall, a lower transverse wall, and an outer wall. Each upper transverse wall and each lower transverse wall includes alternating solid portions and open portions. Each solid and open portion extends from the body to the outer wall of a crushable member. The solid portions of the lower transverse wall of the upper crushable member are aligned with the open portions of the upper transverse wall of the lower crushable member.