FRESNO, Calif. – Relatives of a 24-year-old intern killed by a lion at a California animal park said Friday they believe the facility followed safety protocols and the death was a tragic accident.

Investigators believe the 5-year-old male lion lifted the door of a partially closed feeding cage with its paw and killed Dianna Hanson as she cleaned a bigger enclosure area, Fresno County Coroner David Hadden has said.

Family members said they’re relieved the young woman was killed instantly when the lion swiped or lunged at her.

“We’re thankful to know she didn’t suffer,” said Hanson’s brother, Paul R. Hanson.

Dianna Hanson died immediately from a broken neck, according to the coroner’s autopsy report. Other injuries were sustained after her death, the report says.

Family members said they don’t believe it was a mauling, but rather a lion’s rough play that turned tragic.

“It sounds like it was an accident, maybe the latch had not been completely closed. … You know, house cats are smart, they can open doors,” Paul Hanson said. “It wasn’t a vicious attack … because you would expect severe lacerations and biting on the neck and that was not the case.”

Paul Hanson and his wife, Tiffany Windle-Hanson, said they don’t believe any rules were broken at Cat Haven, the animal park run by the nonprofit group Project Survival.

“It was just a tragic accident,” Windle-Hanson said.

Investigators were focusing on the cage door that the 550-pound animal managed to escape through to reach the volunteer intern.