ORLANDO, Fla. — Tilikum the orca has died after more than two decades at SeaWorld Orlando, where he gained notoriety for killing a trainer in 2010 and was later profiled in a documentary that helped sway popular opinion against keeping killer whales in captivity.

He will not be replaced. He was the first of SeaWorld's orcas to die since the company announced the end of its orca breeding program in March 2016.

In a statement announcing Tilikum's death early Friday, SeaWorld officials said he had serious health issues including a persistent and complicated bacterial lung infection. Tilikum was estimated to be 36 years old. A necropsy will determine the cause of death.

The 2010 death of SeaWorld trainer Dawn Brancheau during a performance with Tilikum after a "Dine with Shamu" show shocked the public and changed the future of orcas at SeaWorld parks.

Brancheau was interacting with Tilikum before a live audience at SeaWorld Orlando when he pulled her from a platform by her arm and held her underwater. An autopsy report said Brancheau drowned but also suffered severe trauma, including multiple fractures.

Former SeaWorld orca trainer John Hargrove said Tilikum's death offered some closure in the violent death of his friend and colleague. But he said Tilikum also finally found relief.

"Tilikum has been sick, very sick, for so long, and after everything he's had to endure, this is to me like he's free," said Hargrove, who left SeaWorld in 2012 and was featured in the documentary "Blackfish."

"He lived a tortured existence in captivity. I think all the whales do, but if you had to pinpoint one of them, hands down I would say Tilikum."

Animal rights advocates who want orcas and other marine mammals at SeaWorld parks released into sea pens or coastal sanctuaries said Tilikum was snared in a business model that led only to tragedy. Lisa Lange, senior vice president for the group People for the Ethical Treatment of Animals, urged SeaWorld to release its remaining orcas and marine mammals to "spend the rest of their lives in as natural a setting as possible."

SeaWorld supporters found something worthwhile in Tilikum's time at the park.

"His story is a complicated one, but I also think he represented his species well," said Grey Stafford, president of the International Marine Trainers' Association. He's also a former SeaWorld employee, though he never worked with Tilikum. "In retrospect, there are a lot positives to say."

SeaWorld President and CEO Joel Manby said, "Tilikum had, and will continue to have, a special place in the hearts of the SeaWorld family, as well as the millions of people all over the world that he inspired."

According to National Oceanic and Atmospheric Administration figures , male killer whales in the wild typically live about 30 years and females typically live about 50 years. Institutions displaying marine mammals and their critics disagree over whether orcas' life expectancy in captivity differs from their life span in the wild.

Tilikum had been SeaWorld's most prolific male orca, siring 14 calves since his arrival at the park about 25 years ago. He was noticeable for his size at more than 22 feet and 11,800 pounds.

He was born off the waters of Iceland and brought to Sealand of the Pacific in Canada after being captured. While at Sealand in 1991, Tilikum and two female orcas were responsible for the death of a part-time trainer who fell into their pool and was submerged by them.

Tilikum was moved to SeaWorld Orlando in 1992, and Sealand later closed.

SeaWorld's decision to end the breeding program and phase out the theme parks' traditional orca performances came three years after the release of the documentary, "Blackfish," which chronicled Tilikum's life and Brancheau's death.

Her death was not the only one linked to Tilikum at SeaWorld. In 1999, a naked man who had eluded security and sneaked into SeaWorld at night was found dead the next morning draped over Tilikum in a breeding tank in the back of Shamu Stadium.

"Blackfish" argued that killer whales in captivity become more aggressive toward humans and each other. Because of it, several entertainers pulled out of planned performances at SeaWorld parks and animal rights activists increased their demonstrations outside the parks.

SeaWorld attendance dipped, company profits fell and Southwest Airlines ended its 25-year relationship with the theme park company.

Gabriela Cowperthaite, who directed "Blackfish," said in an email that it's time to focus on other whales in captivity. "He lived a horrible life, he caused unspeakable pain, so at least his chapter is over," she said.

In March, SeaWorld's CEO acknowledged that the public's attitude had changed about keeping killer whales captive.

"We needed to move where society was moving," Manby said.

Tilikum's death was another blow for SeaWorld employees already reeling from job cuts announced last month across SeaWorld Entertainment Inc.'s 12-park system, Stafford said. He worried the loss of employees trained to care for marine mammals may inadvertently weaken other conservation efforts, such as a captive breeding program proposed for endangered porpoises called vaquitas in the waters off Mexico.

"That human experience isn't likely to be replaced," Stafford said.