Carr, 40, got trapped in a rock structure which was on fire in Riverside Park in the early morning hours of March 31.
Initially it was believed Carr had attempted suicide. Coroner Barb McClintock said in a statement that Kamloops firefighters were able to rescue her from the fire alive.
"Preliminary indications are that Ms. Carr had set the blaze and then ended up in it accidentally," she said.
Carr was transported to Royal Inland Hospital in Kamloops but succumbed to her injuries several hours later.
'Ritual gone horrifically wrong'
Carr started a Facebook page, Being Pagan Out of the Broom Closet, last year. This Monday, her husband Stephen Carr posted a message announcing Carr's death.
"Heather passed away yesterday from severe burns suffered in a ritual gone horrifically wrong."
Fire chief Les Noel said Carr was stuck among large boulders in an artistic rock garden in the park when firefighters got there.
A passerby had tried to put out the fire with a bucket of water from a nearby river, but when emergency crews arrived, they found Carr with severe burns, still partially trapped inside the rock structure.
Noel said firefighters had to create an opening in the base of the structure in order to extract her.
Three firefighters were also taken to hospital for observation because of smoke and dry chemical inhalation they suffered in extinguishing the fire.
Grief counsellors were also called in to help the firefighters involved in the rescue.
The BC Coroners Service and RCMP are continuing to investigate Carr's death.