Paranormal investigator Dan Rivera passed away just a few hours after concluding a sold-out event featuring the notorious Annabelle doll in Gettysburg, Pennsylvania.

Fox News Digital verified Rivera’s “unexpected and tragic” death with the New England Society for Psychic Research (NESPR). He passed away after being found unresponsive in his hotel room on Sunday. He was 54 years old. 

First responders attempted CPR, but were unable to revive Rivera, according to reporting from the Evening Sun.

The Gettysburg event was the last stop of the “Devils on the Run” tour, which featured haunted artifacts from NESPR’s collection. Ghostly Images of Gettysburg, the host of the event, stated in a Facebook post, “Dan was a wonderful man and a dear friend of ours. He will be missed by all who knew him.”

The Annabelle Raggedy Ann doll sits in a case in the Warren’s Occult Museum. (Jessica Moore/Hartford Courant/Tribune News Service via Getty Images)

In 1970, a Connecticut nurse reported that the doll moved on its own, left disturbing notes, and physically attacked her friend.

At the time, a psychic claimed the spirit of a 7-year-old child named Annabelle Higgins was inside the doll, but Ed and Lorraine Warren didn’t buy it. The Warrens, seasoned paranormal investigators and founders of NESPR, concluded the presence wasn’t a lost child at all, but a “malevolent entity” using the guise of innocence to manipulate and ultimately harm. 

According to their case files, the spirit’s activity escalated from movements to disturbing notes, then to physical attacks. The Warrens had the doll removed from the home into their museum.

Since the museum closed in 2019, the doll has traveled across the country only under strict NESPR supervision. “She is never out of our control,” NESPR director Tony Spera told Newsweek back in May.

In this photo shared to Rivera’s Instagram page, the paranormal investigator poses for the camera amid curio of the unexplained. (Instagram/ dan_rivera_nespr)

“[Rivera] cared for Lorraine towards the end of her life,” said Paranormal State’s Ryan Buell in a tribute posted online. “When I got clean, Dan believed in me. He wanted me to come back home. He believed in me when I struggled to believe in myself.” Buell also shared some of Rivera’s work behind-the-scenes, writing “He helped haunted families. He carried the Warrens’ mission forward. I also mourn his unfinished dreams and ideas for the future.”

Officials say Rivera’s death is not considered suspicious. The Adams County Coroner has confirmed there are no signs of foul play. An autopsy is pending, which is standard for deaths outside a hospital.

NESPR said the tour will continue in his honor. NESPR shared Rivera’s own words in its statement: “In life we leave a piece of ourselves with loved ones and friends. So, I say I will never die. My journey has only begun.”