When it went on the air in September 1927, the service was the precursor to the entire network, giving a youthful William S. Paley a start in the business. Famed broadcaster Edward R. Murrow’s rooftop reports during the Nazi bombing of London during World War II kept Americans listening anxiously. Today, CBS News Radio provides material to an estimated 700 stations across the country and is known best for its top-of-the-hour news roundups. The service will end on May 22, the network said Friday. “Radio is woven into the fabric of CBS News and that’s always going to be part...