Detroit Lions defensive back Jack Christiansen in his college days at Colorado State University. (National Football League)

Jack Christiansen, appointed Head Coach of the 49ers, addresses sports writers at his first press conference, held at practice headquarters for the 49ers in Redwood City, Calif., Sept. 30, 1963. The 34-year-old Christiansen replaces former coach Red Hickey, who resigned earlier in the day. Christiansen has been an Assistant Coach for the 49ers for the past five years. (Associated Press)

Jack Christiansen, left, head coach for the last eleven 49er games, holds a pen over his 1964 contract as 49er President Vic Morabito looks on, Dec. 23, 1963 in San Francisco. The contract was signed in the club office, giving Christiansen a full season at the helm. He replaced Red Hickey, who resigned after a poor showing by the team during early games of this season. (AP Photo/Robert W. Klein)

Jack Christiansen, former San Francisco 49ers coach, poses in Palo Alto, Calif., Feb. 2, 1970 after being named to the Professional Football Hall of Fame. Christiansen is now an assistant coach at Stanford. (Associated Press)

Detroit Lions safety Jack Christiansen (24) poses for a photo during training camp at Cranbrook Educational Community in Michigan, Aug. 22, 1957. (Pro Football Hall of Fame)

Detroit Lions safety Jack Christiansen (24) poses for a photo during training camp at Cranbrook Educational Community in Michigan, Aug. 12, 1958. (Pro Football Hall of Fame)