A member of one of the NFL's founding families has died.

FOX's Chris Hoenig reports:

Dan Rooney, Chairman of the Pittsburgh Steelers, has died...

He was the son of team founder Art Rooney, a ball boy in his teenage years and running the team by the time he was in his early 30's.

Rooney was a mentor to current Commissioner Roger Goodelll, even breaking the news to him that he had been selected by the owners for the position back in 2006.

In 2000, he was elected to the Pro Football Hall of Fame, and two years later, turned day-to-day control of the Steelers over to his son, Art Rooney II.

From 2009 to 2012, Rooney also served as the U.S. Ambassador to Ireland.

Dan Rooney was 84-years-old.

Chris Hoenig, FOX News.

Follow Chris Hoenig on Twitter: @Chris_Hoenig