The investigative report released Wednesday by the Orange County Sheriff's Office in Orlando, Fla., includes a park surveillance video that captured the Feb. 24 attack, accounts from horrified witnesses and statements from SeaWorld employees who tried to rescue Brancheau, 40, after Tilikum pulled her underwater by her ponytail.
Brancheau died of drowning and blunt-force trauma to her head, neck and torso, according to the medical examiner, who ruled the death an accident. A previously released autopsy report also revealed Brancheau's left arm had been torn off.
According to park visitor Jessica Wilder of Vermont, Brancheau was "hugging" Tilikum and feeding him fish shortly after a "Dine With Shamu" show, during which the public could take photos outside Tilikum's tank. Fellow trainer Jan Topoleski told investigators that Brancheau was interacting "nose to nose" with Tilikum in a shallow pool when her "long hair floated on the water into Tilikum's mouth."
Topoleski said she rushed to sound an alarm, but when she turned back to Brancheau, she was "nowhere to be seen."
Wilder said she saw Brancheau "scrambling to get out of the water," but the whale "impacted her squarely in the chest," looping around and coming at the trainer with his mouth agape.
According to the report, at about 1:38 p.m., after Tilikum pulled Brancheau into the water, she is seen swimming underneath him, briefly free from his grip. Seconds later, as she attempts to swim to the surface, the report said, Tilikum can be seen striking Brancheau repeatedly, swimming underwater "in what appeared to be an agitated state" and doing a "deep dive" while clutching the trainer in his mouth.
In video time-stamped four minutes later, Brancheau is reported to "appear lifeless" as the whale clutches her by the torso.
Topoleski and other employees told investigators they attempted to corral Tilikum to a medical pool using nets, but they said even after netting the orca, he did not release Brancheau from his grip. Employee Chahine Kish, who witnessed the rescue attempt, said the whale became increasingly "frantic," coming to the pool's surface only long enough to breathe.
Another employee, animal trainer Craig Thomas, said the orca was holding Brancheau by her hair but "periodically changed position to holding her by the arms and legs."
Only after raising the floor of one of the pools, breaching the whale, were trainers able to extract Brancheau from his mouth.
Paramedic Thomas Tobin told investigators he waited for approximately 30 minutes outside the pool wall before Brancheau was freed from Tilikum's jaws.
SeaWorld staff members quoted in the report said the 27-foot whale, who has been linked to three other SeaWorld deaths, had a history of "possessive behavior," refusing to release toys during training sessions. Trainer Lynne Schaber told investigators she feared for Brancheau's safety immediately after the attack began because Tilikum "normally keeps things that he has and will not release them."
Chuck Tompkins, SeaWorld Parks and Entertainment's corporate curator of zoological operations, said of Tilikum, "I truly believe he looked at Dawn as an object, a toy."
Investigators said trainers told them that while Tilikum was deemed "to have tendencies that make him unsafe," the whale showed no signs of agitation or "unwillingness to perform" on the day of the attack.