Devastated friends are mourning the death of a devoted nurse fatally struck by a motorcyclist while biking home from an overnight shift at a Brooklyn hospital. Clara Kang, 31, was cycling east along 56th St. in Sunset Park after her overnight shift at NYU Langone Hospital-Brooklyn when she was struck by a motorcyclist at Third Ave about 7:30 a.m. Saturday. The crash sent both riders flying through the air.