Lowry Mays, 73
One morning, in the spring of 2004, Mays awoke to a numbing sensation and was rushed to the hospital room for emergency brain surgery to relieve pressure caused by a blood clot. While he recovered, his son Mark took over as interim CEO of the company Lowry founded. Six months later, Mark replaced him permanently, though Clear Channel didn't explain the timing of the decision.
NEXT: Ann Livermore, 50
