James Kennedy, Who Inspired the Movie ‘Radio,’ Dies at 72

James R. Kennedy, who inspired the 2003 film “Radio” and was a staple on the sidelines of his high school’s football team in South Carolina, died on Sunday. He was 72.

T.L. Hanna High School in South Carolina, where he was a fixture for decades, confirmed his death on its website. The school did not specify the cause of death or say where he died.

Mr. Kennedy, who had developmental disabilities, showed up on the football field in the mid-1960s and became an integral part of the school, Sheila Hilton, a former principal there, said in a post on the school’s website.

As a teenager, Ms. Hilton said, Mr. Kennedy could barely speak, was unable to read or write, and carried a transistor radio — the origin of his nickname, Radio.

“He became a fixture at football practices, standing passively and watching, until one day when he began to mimic the coaches’ signals and tried his hand at yelling out commands,” she wrote. “At that point, he could have been labeled a distraction and sent away. But he was not.”

“Radio,” which starred Cuba Gooding Jr. as Mr. Kennedy and chronicled the friendship between him and Harold Jones, a T.L. Hanna football coach, was inspired by a 1996 Sports Illustrated article, “Someone To Lean On,” by Gary Smith.

Both the article and the film detailed how Mr. Kennedy, under Mr. Jones’s mentorship, went from being an outcast to a beloved member of the community. The high school is in Anderson County School District Five, about 125 miles west of Columbia.

“When Radio dies, it’ll be the biggest funeral in the history of Anderson,” one assistant football coach at the high school told Mr. Smith. “It’ll be like a senator’s or a governor’s funeral.”

After Mr. Jones retired in 1999, the two men took trips together and shared “a desire to help others through service,” according to a website about their friendship.

Mr. Kennedy was considered a permanent high school junior, meaning that he would never graduate or have to leave.

James Robert Kennedy was born on Oct. 14, 1947, according to the high school’s website, which did not include the names of his parents or say where he was born. Information on survivors was not immediately available.

Mr. Kennedy came to T.L. Hanna in 1965, according to the high school, but Mr. Jones said their friendship began in fall 1964.

Messages mourning Mr. Kennedy were posted on social media on Sunday.

“Thank you for living a life that inspired millions,” the T.L. Hanna football team said on Twitter. “The sidelines won’t be the same without you.”