Carolyn Reidy, president and CEO of Simon & Schuster since 2008, died of a heart attack this morning. She was 71.

News of Reidy’s death was delivered to shocked S&S employees by Dennis Eulau, the company’s executive v-p of operations and chief financial officer, who had worked with Reidy for 25 years. In his note, Eulau called Reidy “a fierce leader, loyal friend, and passionate supporter.” He pointed to Reidy’s “rare combination of business acumen and creative genius that made her a once-in-a-lifetime publishing executive.”