SeaWorld has announced the passing of Tilikum, the orca whale that killed its trainer.
One of SeaWorld's better-known orca whales, Tilikum, who killed trainer Dawn Brancheau in 2010 and inspired the movie 'Blackfish,' died on Friday.
It is unclear what killed him, but a necropsy is planned to pin down the cause of death.
Veterinarians had been treating Tilikum for a "persistent and complicated bacterial lung infection," according to USA Today.
He was estimated to be 36 years old.
SeaWorld received a lot of backlash for its treatment of Tilikum over the years.
Last year, California became the first state to shut down killer whale shows and breeding.
USA Today reports SeaWorld ended its killer whale breeding program in March and has announced plans to phase out theatrical shows.
SeaWorld operates parks in California. Florida, Virginia and Texas.
Here is footage from the 2010 attack featured in the Blackfish documentary.