Radio pioneer Ed Walker was 83 years old. On October 15 Walker announced he was going off the air after being diagnosed with cancer. Last week he recorded his final Sunday night show called "The Big Broadcast" for WAMU from his hospital room. That final show was aired yesterday. WTOP reports Walker listened to his final broadcast and died three hours later. WAMU tweeted, "We are very sad to announce our friend Ed Walker passed away this morning, after listening to his final show with his family."