The story behind Tilikum the killer whale
With a name meaning friend in Chinook, killer whale Tilikum was captured near Iceland in November 1983 at around two years of age.
At 22 feet 6 inches long and weighing in at 12,300 pounds he is the largest orca in captivity.
His immense size, illustrated by his dorsal fins which are six and a half feet long, means he is more difficult to manage than other orcas in captivity.
Handlers are unable to swim with Tilikum because of the ever present danger of being crushed or drowned as he moves around his tank.
Following his capture he was shipped to the Sealand of the Pacific public aquarium in British Columbia, Canada, where he lived with two females Nootka IV and Haida II.
But Tilikum failed to bond well with the pair and would often be bullied and chased by them around their tank.
Despite the difficult relations it was at Sealand of the Pacific where he sired his first calf, a son with Haida II.
Kyuguot was born on December 24 1991 and was the first of 13 calves sired by Tilikum, making him the most successful breeding killer whale in captivity.
A few months before the birth tragedy struck however, when a part time orca trainer slipped and fell into the pool following a show.
Despite efforts to rescue her, the three killer whales dragged and repeatedly submerged the 20-year-old student until she drowned.
Sealand of the Pacific closed down operations shortly after the incident and in January 1992 Tilikum was sold to Seaworld Orlando.
He became a key part in the park's successful breeding programme even being trained to participate in the process of artificial insemination.
In 1999 Tilikum was again implicated in the death of an individual after the body of a 27-year-old man was found floating in the pool.
The man had entered the park after it had closed and had somehow got into the pool containing the orca.
Investigators discovered he had been bitten by Tilikum, but it was never established whether this occurred before or after death, and it was ruled the man had died as a result of hypothermia and drowning.
As an Icelandic orca his diet consists mainly of herring but killer whales are at the top of the food chain with no natural predators and in the wild regularly feast on larger mammals including sea lions, seals and walruses.
With killer whales likely to live into their 60s, Tilikum remains a relatively young animal, but despite calls from conservationists it is unlikely he could ever be released back into the wild.
Having being captured when he was just two he will not have learnt the skills to hunt properly and is therefore entirely dependent on humans.
The tragic death of 40-year-old trainer Dawn Brancheau has once again reopened the debate as to the ethics of keeping such large, intelligent and dangerous animals in captivity.