The cause of death is not known at this time.
Hatley is survived by his wife, Claudia; daughter, Eliza; and two grandsons. Tuesday was his 30th wedding anniversary.
Known as a good guy in football, Hatley will be remembered as a unique character that often stood on the sidelines with his hands in his pockets surveying his team.
"Mark loved football and excelled in evaluating the game and the people who play it. But as talented as he was in his professional career, it was Mark's personal qualities that made him a special individual. Mark made life fun with his endless energy and quick wit. He was dedicated to his job and his family. We were fortunate to have Mark as a part of our team. The Bears, and the rest of the NFL, have lost a wonderful friend."
Hatley had several catch phrases that kept those in his company at ease.
"We're going to see where we're at on the thing," was often his answer to any question from the media.
The Bears hired Hatley in 1997 and he stayed in Chicago until 2001. Between that time he drafted consecutive rookies of the year in Brian Urlacher (2000) and Anthony Thomas (2001). Hatley left the Bears shortly after the ‘01 draft and spent the past three years as the Packers vice president of football operations.
While in Chicago Hatley had late round success with players like Kreutz, Marty Booker, Rex Tucker Rosevelt Colvin, Warrick Holdman and Paul Edinger, none of whom were selected earlier than the third-round. Patrick Mannelly might not be in the league if Hatley didn't take a chance on him in the sixth-round of the '98 draft. He's now one of the best long snappers in the game.
"He's the guy that brought me in the NFL," Mannelly said. "Very fortunate for him finding me at Duke and bringing me here. It's a very sad day to hear that he passed away. It's a shocker."
A native of Borger, Texas, Hatley played linebacker at Oklahoma State, leading the Cowboys in tackles in 1971 before beginning his coaching career at OSU from 1973-75. He also worked at Tulsa, Texas Christian and Baylor before joining the New Orleans Saints' coaching staff in 1984. He joined the Chiefs as linebackers coach in 1987 before moving to the personnel side of the game in 1992 as pro personnel director for the Kansas City Chiefs.