Deputies in California will keep open an investigation into a golf cart accident reportedly involving Denver Broncos legend John Elway but say all witnesses have been interviewed, and nothing indicates foul play was involved.

TMZ reported John Elway was driving a golf cart at The Madison Club in La Quinta, California, April 26 when his longtime agent and friend, Jeffrey Sperbeck, 62, fell out and hit his head.

The two were leaving a Stagecoach after-party, the outlet reported.

A spokesperson for Cal Fire told Fox News Digital Sperbeck sustained “serious injuries” and was transported to a hospital. He was initially listed in critical condition, but he died April 30.

John Elway said he was “devastated” by his friend’s death. (Kirby Lee/USA Today Sports)

In a statement released after Sperbeck’s death, Elway said he was “devastated,” according to ESPN.

“I am absolutely devastated and heartbroken by the passing of my close friend, business partner and agent Jeff Sperbeck,” Elway said. “There are no words to truly express the profound sadness I feel with the sudden loss of someone who has meant so much to me.”

Sperbeck’s family also released a statement.

“We are deeply saddened to share the passing of our beloved Jeff Sperbeck. He was a wonderful father, husband, brother, son and friend to many and will be profoundly missed by all,” the Sperbeck family said. “We are grieving this unimaginable loss as a family alongside our dearest friends the Elway’s and the many other clients Jeff called friends.”

John Elway warms up before the Super Bowl against the Atlanta Falcons in Miami Jan. 31, 1999. (Robert Deutsch/USA Today Network via Imagn Images)

Sperbeck became Elway’s manager in 1990. Among Sperbeck’s clients were Pro Football Hall of Famers Ronnie Lott and Jim Plunkett, in addition to hundreds of other NFL players.

Fox News’ Chantz Martin and Scott Thompson contributed to this report.