Kayla, a 30-year-old female orca at SeaWorld Orlando, died Monday morning after a short illness, the theme park announced.

According to SeaWorld, Kayla began showing “signs of discomfort” on Saturday, with her condition worsening on Sunday.

“Although animal care specialists and veterinarians devoted around the clock attention to Kayla, she did not survive,” the park said in a statement. “While today is a difficult day for all of us at SeaWorld, Kayla inspired generations of guests and employees to care and learn more about this amazing species.”

Determining the cause of death may take several weeks, until the results of a “post-mortem examination are complete,” SeaWorld said.

Kayla was born in captivity in 1988 at SeaWorld San Antonio, spending some time at the since-shuttered SeaWorld Ohio before returning to Texas. She later gave birth to a calf named Halyn in 2005, but according to David Kirby’s book “Death at SeaWorld,” Kayla rejected Halyn, forcing park staff to take over nursing responsibilities. Kayla moved to the Orlando park in 2006, while Halyn died in 2008.

Naomi Rose, marine mammal scientist at the Animal Welfare Institute, told Orlando Rising that Kayla’s repeated moves between parks were “no doubt stressful and do not reflect natural movements for these family-bonded whales at all.”

“Kayla was the second oldest captive-born orca ever. She was 30. That’s prime of life in the wild,” Rose said. “It is very unusual for a wild female orca living in good habitat to die at 30. Unfortunately it’s not uncommon in captivity at all.”

Kayla is the fourth SeaWorld orca to have died over the last two years. In January 2017, Tilikum — the subject of the “Blackfish” documentary who had been involved in three human deaths — died in Orlando, with the cause of death never released by the company. 3-month-old Kyara, the last killer whale born in captivity under the park’s former breeding program, died the following July at the San Antonio park. An orca kept at SeaWorld San Diego, Kasatka, was euthanized after a battle with a lung disease a month later.

Animal rights group PETA has sued to gain access to the autopsy and veterinary records for the deceased whales. A PETA spokesperson told Orlando Rising Kayla’s records would not be covered by that lawsuit, but it hopes SeaWorld will release them anyway “in the interest of public disclosure and accountability.” The group also plans to hold two protests outside the Orlando park on Wednesday and Saturday.

“While we recognize that it’s too late to help her, it’s not too late to call attention to SeaWorld’s other orca prisoners, who must be released into seaside sanctuaries as soon as possible,” said Tracy Reiman, PETA’s executive vice president.

The news of Kayla’s death follows a year where SeaWorld appeared to turn its fortunes around after a long post-”Blackfish” slump. Through the first three quarters of 2018, the company reported a 8.7 percent jump in attendance and a 9.5 percent increase in revenue.