Gill Dennis, who co-penned the screenplay for the Johnny Cash biopic “Walk the Line,” has died. He was 74.

Dennis died in his Portland, Ore. home, according to the American Film Institute. AFI was unable to confirm the date of his passing at this time.

Dennis also wrote the screenplays for Walter Murch’s “Return to Oz” (1985) and Judy Davis’ drama “On My Own” (1991), in addition to penning and directing Angelina Jolie’s thriller “Without Evidence” (1995) and the 1973 film “Intermission.” On the TV front, he did the teleplay for the 1996 TNT Western “Riders of the Purple Sage” and wrote the Showtime miniseries “Home Fires.”

Dennis was a 1969 graduate of the AFI Conservatory’s first class, which also included Terrence Malick, David Lynch and Caleb Deschanel. He returned to AFI in 1997 as a master filmmaker-in-residence and taught the incoming class this past September. His students took to Twitter to express their grief.

Dennis was once married to actress Elizabeth Hartman, who committed suicide in 1987, a few years after their divorce.

He is survived his wife, Kristen Peckinpah Dennis, and two sons.

Dennis talks, in the video below, about collaborating when writing screenplays before a screening of “Walk the Line” at the AFI Silver Theater and Cultural Center in Silver Spring, Md. He co-wrote the film, starring Joaquin Phoenix and Reese Witherspoon, with director James Mangold.