In 1987 alone, SeaWorld San Diego experienced three incidents that hospitalized trainers with everything from fractured vertebrae to a smashed pelvis. Jonathan Smith was one of them. In March, during a show, he was grabbed by two killer whales, who slammed him on the bottom of the thirty-two-foot-deep pool five times before he finally escaped. "One more dunk for me and I would have gone out," he says. "They let me go. If they didn't want to let me go, it would have been over." Smith was left with a ruptured kidney, a lacerated liver, and broken ribs. In response to these serious injuries, as well as other incidents, SeaWorld shook up its management team, pulled trainers from the water, and reassessed its safety protocols. After a number of changes (including making sure that only very experienced trainers worked with killer whales), trainers were allowed back in the pools.

  Despite the modifications, in 2006 another serious incident took place at SeaWorld San Diego, when head trainer Kenneth Peters was attacked by a killer whale called Kasatka. Kasatka grabbed Peters and repeatedly held him below the surface of the pool for up to a minute. He came close to drowning, and Kasatka joined Tilikum and a couple of other unruly SeaWorld orcas on the "no water work" blacklist.

  Following the Peters incident, OSHA opened an investigation. After digging into the inner workings of SeaWorld's killer whale shows, OSHA issued a report in 2007 that warned, "The contributing factors to the accident, in the simplest of terms, is that swimming with captive orcas is inherently dangerous and if someone hasn't been killed already, it is only a matter of time before it does happen." SeaWorld challenged the report as filled with errors, and OSHA agreed to withdraw it.

  In late March 2010, a month after Brancheau's death, I visit Orlando's SeaWorld park for the first time. I pause for an instant to take in the sheer size of the place, with its hundreds of diversions, but there is just one thing I really want to see: a killer whale show. I thread my way through families and packs of ecstatic kids. Shamu Stadium, SeaWorld's colossal amphitheater, looms before me.

  The current Shamu show is called "Believe," and Dawn Brancheau was one of the stars. Music, video, and killer whales are wrapped around the story of a kid who paddles out to bond with a wild orca and is inspired to become a trainer. Every element is intimately choreographed, with whales exploding into the air and on-screen in perfect synchronicity. Even though Brancheau's death has prompted SeaWorld to temporarily reinvent "Believe" without trainers in the water, it is still absolutely mesmerizing. The show builds to a climactic finale with a pack of orcas lining up and using their flukes to sweep a tidal wave of water onto the shrieking and willing inhabitants of the splash zone.

  After the show I sit down with Brad Andrews in front of the underwater viewing area of G pool. Two killer whales are amusing a crowd of people who probably have no idea of the scene the same windows revealed a month earlier. Andrews is SeaWorld's chief zoological officer, and he's been with the park since 1986. He explains that while part of the goal is entertainment, SeaWorld's aim is to use the shows to educate and inspire visitors, as a way to help conserve the environment and support wildlife.

  There's a lot of criticism that flies back and forth between SeaWorld and the hard marine-science community, but there's no question that SeaWorld's close contact with killer whales over the course of decades has contributed to the world's knowledge of them. "The gestation of killer whales was never known to researchers in the wild. It was always assumed it was like a dolphin, twelve months," Andrews says. "Then we found out it's seventeen to eighteen months. We supplied an answer to a part of their puzzle."

  The advances SeaWorld has made in veterinary care have also paid off when it comes to rescuing stranded or sick marine animals, and SeaWorld's state-of-the-art breeding techniques could be useful in trying to preserve marine mammal populations on the brink of extinction, such as the vaquita porpoises in the Sea of Cortez. SeaWorld also nurtures multiple partnerships with leading conservation nonprofits, from the World Wildlife Fund to the Nature Conservancy. "Every year we spend $3 million to $4 million on research and conservation programs outside our park and another $1.5 million on rescuing stranded animals," Andrews says.

  Head trainer Kelly Flaherty Clark still has faith in the benefits of SeaWorld's mission in the wake of Brancheau's death. One of her mantras, known around the park as "Kellyisms," is "Do the right thing." As we sit together in the stands of Shamu Stadium, "Believe" looks like pure family fun. But for the trainers, the shows are the product of countless hours of hard work and practice. They know there are risks. "These are not dogs," Flaherty Clark says. "Every day you walk into your job, you are walking into a potentially dangerous situation. You never forget that. You can't afford to forget that."

  SeaWorld doesn't forget, and conducts safety and rescue training once a month. Among other things, trainers are taught to go limp if they are grabbed, so the whales will lose interest. The killer whales are taught to keep their mouths closed while swimming and are desensitized so they stay calm and circle the perimeter of the pool if someone accidentally falls in. They learn emergency recall signals—transmitted via a tone box and hand slaps—and are trained to swim to a pool exit gate if a net is dropped in. Scuba gear is always nearby. SeaWorld's intensive regime helped its trainers interact with killer whales more than two million times without a death. But when a killer whale breaks from its training, all bets are off.

  It's hard to know exactly what triggers an incident. It could be boredom, a desire to play, the pent-up frustration of confinement, a rough night in the tank with the other orcas, the pain of an ulcer, or maybe even hormonal cycling. Whatever the motivation, some trainers believe that killer whales are acutely aware of what they're doing. "I've seen animals put trainers in their mouths and know exactly what the breaking point of a rib cage is. And how long to hold a trainer on the bottom," says Jeffrey Ventre, who was a trainer at SeaWorld Orlando from 1987 until 1995, when he was let go for giving a killer whale a birthday kiss, in which he stuck his head into an orca's mouth.

  If you're a killer whale in a marine park, there's probably no better place than SeaWorld. Yet no matter how nice the facility, there's stress associated with being a big mammal in a relatively small pool. Starting at Sealand, Tilikum had developed the habit of grinding his teeth against metal pool gates. Many of his teeth were so worn and broken that SeaWorld vets decided to drill some of them so they could be regularly irrigated with antiseptic solution. And once again he had to deal with the stress of hostile females, particularly a dominant orca called Katina. "Tili was a good guy that got beat down by the women," says Ventre, now a doctor in New Orleans. "So there are a lot of reasons he might be unhappy."

  John Jett, who was a team leader for Tilikum, says he sometimes would suffer a beatdown bad enough to rake up his skin and bloody him and would have to be held out of shows until he healed. Jett had a term for the blood left streaming in the water: "sky writing." After a good thrashing from the other orcas, Jett says, Tilikum might be "off" for days, "splitting" from his trainer to swim at high speed around the pool, acting agitated around the females, or opening his eyes wide and emitting distress vocals if asked to get into a vulnerable position (like rolling over on his back). "It's extremely sad if you think about being in Tili's situation," says Jett. "The poor guy just has no place to run."

  SeaWorld's Fred Jacobs denies that Tilikum was ever held out of shows due to injuries from other orcas. "Injuries as part of the expression of social dominance are rare and almost never serious," he says. "We manage Tilikum's social interaction on a daily basis."

  In 1999 Tilikum reminded the world that, at least when it came to humans, he could be a very dangerous animal. Early on the morning of July 6, Michael Dougherty, a physical trainer at SeaWorld, arrived at his office near the underwater viewing area of G pool. He glanced through the viewing glass and saw Tilikum staring back, with what appeared to be two human feet hanging down his side. There was a nude body draped across Tilikum's back. It wasn't moving. As in the Brancheau i
ncident, Tilikum was herded onto the medical lift in order for SeaWorld staff to retrieve the body. Rigor mortis had already set in. It was a young male, and again the coroner's and sheriff's reports are telling. He had puncture wounds and multiple abrasions on his face.

  The victim was Daniel Dukes, a twenty-seven-year-old with a reddish blond ponytail, a scraggly beard and mustache, and a big red "D" tattooed above his left nipple. Four days earlier he'd been re-leased from the Indian River County Jail after being booked for retail theft. On July 5 he apparently hid at SeaWorld past closing or sneaked in after hours. At some point during the night, he stripped down to his swim trunks, placed his clothes in a neat pile, and jumped into the pool. Perhaps he was simply crazy or suicidal. Perhaps he believed in the myth of a friendly Shamu.

  The coroner determined the cause of death to be drowning. There were no cameras or witnesses, so it's not known if Tilikum held him under or hypothermia did him in. But it's clear Tilikum worked Dukes over. The coroner found abrasions and contusions—both premortem and postmortem—all over his head and body and puncture wounds on his left leg. His testicles had been ripped open. Divers had to go to the bottom of the pool to retrieve little pieces of his body. SeaWorld ramped up its security, posting a twenty-four-hour watch at Shamu Stadium. Keltie Byrne had not been an aberration.

  If anyone was going to take care around Tilikum, it was Dawn Brancheau. She was one of SeaWorld's best and completely dedicated to the animals and her job. (She even met her husband, Scott, in the SeaWorld cafeteria.) She had worked at SeaWorld Orlando since 1994, spending two years working with otters and sea lions before graduating to work with the killer whales. She was fun and selfless, volunteering at a local animal shelter and often keeping everything from stray ducks and chickens to rabbits and small birds at her home.

  Over time, Brancheau had become one of SeaWorld's most trusted trainers, one of the dozen or so authorized to work with Tilikum. "Dawn showed prowess from the minute she set foot here. There's not one of us who wouldn't say that she was one of the best," says Flaherty Clark. Brancheau knew the risks and accepted them: "You can't put yourself in the water unless you trust them and they trust you," she once told a reporter.

  Perhaps she trusted Tilikum too much. Thad Lacinak, the former vice president of animal training at SeaWorld, thinks so. He says Brancheau was an exemplary trainer, one of the best he'd ever seen in the water. Still, Lacinak thinks Brancheau made a mistake lying down so close to Tilikum's mouth and letting her hair drift in the water alongside him. "She never should have put herself in that vulnerable a position," he says. "One of the things we always talked about at SeaWorld was you never want to get totally comfortable with any animal."

  Former trainer Mark Simmons has been involved in deconstructing previous SeaWorld incidents between trainers and killer whales and was a friend of Brancheau's. He also thinks Brancheau's vulnerable position and hair (which he says she was growing long so she could give it to cancer patients for wigs) were the key factors that led to her being pulled into the pool. "Tilikum has never had an aggressive disposition," he says. "This was not the first time Dawn had lain down next to Tili in that position, but it was the first time her hair was that long and contacted Tili." Simmons believes Tilikum reacted to this "novel stimulus" by taking it into his mouth. When Brancheau tried to tug it free, as spotter Jan Topoleski described, Tilikum suddenly had a tempting game of tug of war, which he was bound to win. (After Brancheau's death, SeaWorld's long-standing policy that long hair be kept in a ponytail was revised to mandate that it be kept in a bun.)

  At least two witnesses, however, told investigators that they saw Tilikum grab Brancheau by the arm or shoulder, which would suggest a more intentional act. Asked how certain he was that Tilikum pulled Brancheau in by her hair, SeaWorld's Fred Jacobs responds, "Witness accounts support that conclusion, and we have no reason to doubt it."

  The second critical question is: Why did Tilikum get so violent once Brancheau was in the water? The coroner cataloged a fractured neck, a broken jaw, and a dislocated elbow and knee. A chunk of skin and hair was ripped from her scalp and recovered from a pool. "When a 12,000-pound animal gets its hands on 'the cookie jar' and responds with the excited burst of energy common in such situations, it can have tragic consequences," Simmons says. "Once the alarm was sounded and emergency net procedures were initiated, Tilikum's behavior became agitated. This is what appears to the untrained observer to [constitute] an 'attack.'"

  Whether the emergency response increased Tilikum's agitation or not, once Brancheau was in the water, her fate was up to a killer whale that hadn't become accustomed to humans in the pool. "He got her down and that was it—she wasn't getting out," says former trainer Jonathan Smith. "I truly believe that they are smart enough to detect and know what they are doing. He's going to know she is trying to get to the surface." Former trainer Ventre agrees. "If they let you out, it's because they decide to," he says. "We don't know for sure what motivated Tilikum. But there's no doubt that he knew exactly what he was doing. He killed her."

  SeaWorld says it is conducting the most exhaustive review in its history. At press time, the review was not complete, and OSHA's report is not expected until late summer.* For the moment, SeaWorld is not taking any chances. No trainers are performing in the water with orcas, and all direct human contact with Tilikum has ceased. "We used to interact very closely with Tilikum but now maintain a safe distance," Flaherty Clark wrote on the SeaWorld blog in March. Where Tilikum once got regular rubdowns and close contact during cleanings and other husbandry, now he's hosed down instead of hand-massaged, and his teeth are cleaned with an extension pole. His isolation has only increased, opening a wider debate about the future of killer whale entertainment.

  After Brancheau's death, Jean-Michel Cousteau, president of the Ocean Futures Society, made a videotaped statement in which he said, "Maybe we as a species have outgrown the need to keep such wild, enormous, complex, intelligent, and free-ranging animals in captivity, where their behavior is not only unnatural; it can become pathological," he said. "Maybe we have learned all we can from keeping them captive."

  Cousteau raises a profound point. But regardless of how this incident affects orca captivity, Tilikum's fate is likely sealed, despite calls for his release back into the wild. Free Willy's Keiko underwent extensive retraining before being released into the seas off Iceland and appears to have foraged for food on his own. But he never reintegrated with a pod. A little over a year later, after swimming to Norway, he died, likely from pneumonia. Ken Balcomb still believes that most marine-park orcas can be taught what they need to know to be returned to the wild. (No real effort was made to find Keiko's family, Balcomb says, which is a key to success.) But even he rules Tilikum out. "Tilikum is basically psychotic," he told me as we looked out over Haro Strait in May. "He has been maintained in a situation where I think he is psychologically unrecoverable in terms of being a wild whale."

  There is one other option. "We have proposed to Blackstone Group a sea-pen retirement," says Naomi Rose, a marine mammal scientist at the Humane Society International. "Tilikum needs more space, more stimulation to distract him. Living as he is, with minimum human contact in a small concrete tank, is untenable."

  SeaWorld's Fred Jacobs dismisses the idea. In addition to citing worries about the impact of taking him out of the social environment he is now accustomed to and about potential threats to his health from pollution and disease, Jacobs says, "All the animals at SeaWorld allow people a really rare privilege to come into contact with these extraordinary animals and learn something about them and maybe when they leave SeaWorld carry that respect forward into their lives. Tilikum is a really important part of that."

  Whether or not Tilikum ever performs again, he's still SeaWorld's most prolific breeder. He's sired thirteen viable calves, with two more on the way this summer. Most likely he will finish his life as he's mostly lived it, in a marine park. He's nearly thirty, and only one male in captivity,
who is still alive, is known to have lived past that age.

  Three thousand miles away, Balcomb often sees a pod of killer whales easing their way through the wilderness of water that is his Haro Strait backyard. They swim with purpose and coordination, huffing spumes of mist into the salty, spruce-scented air. The group is known as L Pod, and one, a big male designated L78, was born just a few years after Tilikum. Balcomb has been tracking L78 for more than two decades. He knows that his mother—born around 1960—and his brother are always close by. He knows that L78 ranges as far south as California with his pod in search of salmon.

  L78's dorsal fin stands proud and straight as a knife, with none of Tilikum's marine-park flop. He hunts when he's hungry, mates with the females who offer themselves, and whistles to the extended family that is always nearby. He cares nothing for humans and is all but oblivious to their presence when they paddle out in kayaks to marvel as he swims. He knows nothing of the life of Tilikum or the artificial world humans have manufactured for him. But Tilikum, before spending twenty-six years in marine parks, once knew L78's life, once knew what it was like to swim the ocean alongside his mother and family. And perhaps, just perhaps, that also helps explain why Dawn Brancheau died.

  Contributors' Notes

  Other Notable Science and Nature Writing of 2010

  Contributors' Notes

  Yudhijit Bhattacharjee has been a staff writer at Science since 2003. His 2008 story on brain trauma caused by explosions on the battlefield won an award for best research writing from the National Mental Health Association. His work has appeared in the New York Times, The Atlantic, the New York Times Magazine, Time, Wired, and Discover.