Every time a child beats cancer at Siteman Kids Children's Hospital, they ring a golden bell. So we set out to replicate the bell ringing ceremony on a scale large enough for the entire city of St. Louis to hear. To do so, we needed to work with municipal government to approve the production of a billboard that would ring at a noise level that could be heard by commuters driving by one of the busiest intersections in the St. Louis area. Our 12-foot tall bell included weather-proof speakers designed to amplify the sound of the bell so it could be heard by commuters from far and wide. A wireless device was hidden in the billboard allowing us to trigger the ringing of the bell on the billboard at the very same time the kids in the hospital were ringing the bell marking the end of their chemotherapy treatments.