CBS Radio’s WOGL-FM Philadelphia is mourning the sudden death of legendary DJ “Big Ron” O’Brien from a bout with pneumonia. "Big Ron was an inspiration to disc jockeys all over the country. We all listened to the energy and excitement that he was able to bring to the radio. He will be missed by many fans. An air personality like Ron can’t be replaced. It is a loss not to be able to hear him on the radio any longer," said CBS Radio CEO Dan Mason. O’Brien’s long on-air career began in 1969 at KUDL Kansas City. After a career spanning numerous call letters, he had been on WOGL in afternoon drive since 2002.