A 26-year-old Bonnaroo attendee who died during this year's festival in Middle Tennessee overdosed on drugs including fentanyl, autopsy findings released Friday show.

Ryan Dunleavy of Brentwood, Tennessee, was found the morning of June 15 in the venue's Manchester's campgrounds, according to Davidson County Assistant Medical Examiner David Zimmerman, who conducted the man's June 16 autopsy.

Dunleavy was found by his father at their Bonnaroo campsite on Pod 11, Zimmerman wrote in his report, and was transported to Unity Medical Center in Manchester with CPR in progress.

He was pronounced dead at the hospital.

According to a toxicology report, Dunleavy had drugs including fentanyl, MDMA (ecstasy) and clozapine in his system when he died.

Autopsy results show Dunleavy's manner of death was accidental.

Coffee County Sheriff's Office deputies found him about 8:15 a.m. after responding to the campground for a medical call.

According to Dunleavy's obituary, he attended Ravenwood High School in Brentwood, graduating in 2011, and later attended Columbia State Community College. Prior to his death, he was employed at McDonald's. The obituary states he had a love of music, from classical to alternative to rock and roll.

On Friday, Coffee County Sheriff Chad Partin said Dunleavy's case was the only fentanyl-related case he was aware of connected to Bonnaroo this year.

Reach Natalie Neysa Alund at nalund@tennessean.com and follow her on Twitter @nataliealund.