TILIKUM, an orca that killed a trainer at SeaWorld Orlando in 2010, has died.

Sea World says in a statement posted online that Tilikum died Friday.

A cause of death had not yet been determined, though the orca was being treated for a persistent bacterial infection.

He was estimated to be 36 years old.

“The SeaWorld family is deeply saddened to announce that one of its most well-known orcas, Tilikum, has passed away. Tilikum passed away early this morning, January 6, surrounded by the trainers, care staff and veterinarians that provided him around-the-clock world-class care,” SeaWorld said in a statement.

“While today is a difficult day for the SeaWorld family, it’s important to remember that Tilikum lived a long and enriching life while at SeaWorld and inspired millions of people to care about this amazing species.”

“Tilikum’s life will always be inextricably connected with the loss of our dear friend and colleague, Dawn Brancheau. While we all experienced profound sadness about that loss, we continued to offer Tilikum the best care possible, each and every day, from the country’s leading experts in marine mammals.”

We’re saddened to announce the passing of Tilikum, a beloved member of the SeaWorld family for 25 years. https://t.co/T7Y3fTgecp pic.twitter.com/vLfpi5szCc — SeaWorld (@SeaWorld) January 6, 2017

Tilikum was profiled in the documentary “Blackfish,” which helped sway popular opinion against keeping killer whales in captivity at SeaWorld parks. As SeaWorld’s most prolific male orca, he sired 14 calves in the nearly 25 years he was at SeaWorld Orlando.

Criticism over keeping orcas captive grew after Tilikum grabbed trainer Dawn Brancheau following a “Dine with Shamu” show and pulled her into the pool by her ponytail, killing her.

Tilikum was also involved in the deaths of two other people in the 1990s.

President & CEO of SeaWorld Joel Manby said his heart goes out to the team that cared for the whale.