Pro Football Hall of Famer John Elway's longtime agent and business partner, Jeff Sperbeck, died from blunt head trauma, the Riverside County Sheriff's Office told TMZ Sports on Friday (May 9).

The determination was made days after Sperbeck died on April 30 and confirmed that the death was ruled accidental.

Sperbeck, 61, and Elway, 64, hadn't attended the local Stagecoach festival earlier in the day, which was previously reported, according to 9News. The group had traveled with roughly 10-15 relatives and friends, which included Elway's son, Jack, his daughter-in-law and comedian Johnny 'Bananas' Devenanzio, according to the report.

The group left a private event hosted by Vouri at The Madison Club later that night and decided not to attend the Stagecoach festival as planned earlier in the day, instead taking three or four golf carts back to Elway's residence on the campus. Elway was driving a single-bench cart with Sperbeck's wife occupying the other seat as Sperbeck and Devenanzio stood on the back of the cart.

Sperbeck was reported to have fallen "straight back" off the car and "hit his head immediately," according to the report. The agent was confirmed to have died from injuries sustained, according to the Riverside County (California) corner in a statement obtained by ESPN last week.