Grady Memorial Hospital's board has ousted chief executive Otis Story , effective immediately, and his position will be filled temporarily by the Atlanta hospital board's chairwoman, state Rep. Pam Stephenson. The decision to fire Story apparently was made following the Grady board's vote to approve a long-discussed plan to transfer power over hospital policy from the Grady board to a nonprofit corporation. Stephenson said she will temporarily give up her law practice to become a full-time executive for Grady.