(CNN) -- A 25-year-old killer whale unexpectedly died at SeaWorld in Orlando, Florida, the park said in a statement Tuesday.
The whale, named Kalina, died Monday evening after a sudden illness, according to the statement.
The cause of death will be determined by a necropsy, the park said, adding that the results could take up to six weeks.
The park said Kalina "showed no signs of illness as recently as Friday" and had a normal appetite Sunday.
"She began exhibiting signs of discomfort Monday afternoon and died suddenly in the evening," the statement said.
Kalina is the third adult whale to die at one of SeaWorld's three locations in four months. In September, 12-year-old male killer whale Sumar died suddenly at the San Diego park, and 20-year-old Taima died while giving birth to a stillborn calf at the Orlando park in June.
The average life expectancy for male killer whales in the wild is about 30 years, while females generally live about 50 years. The average life span in captivity is significantly less.