San Diego's SeaWorld park has lost a killer whale, which marks the third orca that has died in captivity in a SeaWorld park this year.

The death of Kasatka

Kasatka was a killer whale held at SeaWorld San Diego. Kasatka was nearly 42 years old when she passed.

Kasatka was first diagnosed with a lung condition in 2008, where she was treated with a custom-made inhaler. Her condition worsened as she aged. Over the past several days, she stopped responding to her treatment.

Rather than prolong her suffering, park officials decided the best option was to euthanize her in order to end her suffering. This kind of respiratory disease is the most common cause of death in whales and dolphins, both in the wild and in zoos.

Kasatka was not born in captivity but was captured in 1978. Years after she was captured, she was involved in an attack where she took her trainer by the ankle and dragged him under water for more than eight minutes before Kasatka let him go.

Kasatka was loved by many and passed surrounded by members of her clan and staff that cared for her deeply.

Baby Kyara

Kyara was an orca who died at three months old this past July. Kyara was the last orca born at a SeaWorld park, born after they had announced the end of their orca breeding program. Kyara was born last April but conceived before the program ended. Orca's gestational periods can last up to 18 months.

Kyara was being treated for an infection when she passed. The official cause of death has not been determined.

Tilikum's legacy

The killer whale Tilikum has left quite a legacy behind him.

Tilikum was the center around the film "Blackfish," which criticizes the way that SeaWorld treats the Killer Whales that are in captivity and caused quite a stir among animal lovers everywhere as to whether or not the giant mammals should even be kept in captivity.

On January 6, 2017, Tilikum passed away. He was estimated to be 35 years old. Tilikum became part of SeaWorld 25 years ago. Tilikum was another killer whale that passed due to a respiratory infection.

Since the documentary "Blackfish" was released, with Tilikum as the star, SeaWorld announced that the killer whales currently in its care would be the last generation of them being kept in captivity in their water parks. While perhaps more could be done to help these creatures live properly and to the longest of their ability, SeaWorld is clearly listening.

And it's hugely in part to Tilikum, who will live on in people's hearts forever.