From Huffington Post:
Peter Graves, the tall, stalwart actor likely best known for his portrayal of Jim Phelps, leader of a gang of special agents who battled evil conspirators in the long-running television series "Mission: Impossible," died Sunday.I had no idea he was James Arness's brother!
Graves had just returned from brunch with his wife and kids and collapsed before he made it into the house, Brokaw said. One of his daughters administered CPR but was unable to revive him. Graves' family doctor visited the house and believed he had a heart attack, Brokaw said.
Although Graves never achieved the stardom his older brother, James Arness, enjoyed as Marshall Matt Dillon on TV's Gunsmoke, he had a number of memorable roles in both films and television.