Ron Glass, Star of 'Barney Miller' and 'Firefly,' Dead at Age 71

Glass also starred in sci-fi series "Firefly."

— -- Ron Glass, the actor best-known for his role on the 1970s sitcom "Barney Miller" and the sci-fi series "Firefly," has died at age 71.

In a statement to ABC News, Glass' agent, Jeffrey Leavitt, confirms Glass died Friday night of respiratory failure.

"Ron was a private, gentle and caring man. He was an absolute delight to watch on screen," Leavitt said. "Words cannot adequately express my sorrow."

"Castle" star Nathan Fillion, who also starred with Glass in "Firefly," posted a photo on Instagram of Glass with a quote from the show, ending with, "We love you, Ron Glass. Don't go far." Joss Whedon tweeted that Glass had "grace, humor & enormous heart," adding, "He was, among so many other things, my Shepherd."