A great teacher died yesterday. Back in the '90s, Harriett Ball took two rookie Houston teachers under her wing and showed them how to make a classroom a joyous place to learn … and then travelled with Dave Levin and Mike Feinberg through the amazing journey of KIPP, while continuing to teach and consult. We were proud to induct this great lady into the Charter School Hall of Fame along with her KIPP colleagues in 2009. She succumbed to a sudden heart attack on Tuesday. What a legacy she leaves!