The Night the Zoo Burned

After a disaster, a German zookeeper rebuilds.
Firefighters stand in front of a burning enclosure at the Krefeld Zoo.
Fire engulfed the Krefeld Zoo’s ape house in the early hours of New Year’s Day, 2020. One of the surprising things about the fire was how quickly it burned.Photograph by Andreas Drabben / dpa / Alamy

Shortly after midnight on the first day of 2020, five paper lanterns floated over the Krefeld Zoo, in western Germany. The lanterns drifted from a nearby neighborhood, where three women had lit their wicks and watched them lift into the stars. “They even wrote their names and wishes for the new year on the lanterns,” Wolfgang Dressen, the director of the zoo, said. In the morning, the police recovered four lanterns from the trees around the ape house. They believed that the fifth landed on the roof.

Dressen and his wife were ringing in the New Year with old friends in a city called Bielefeld when he received a call, at around half past twelve, from a keeper living at the zoo. The keeper said that the ape house was in flames. Bielefeld is around a hundred and twenty miles from Krefeld, and the Dressens left immediately for home. While his wife drove, Dressen watched videos of the fire on social media. Flames engulfed the roof of the ape house. The smoke was blacker than the sky. After forty-five minutes, one of the zoo’s veterinarians called with an update. “She said they assumed no animals survived,” Dressen recalled.

The ape house was home to five orangutans, two gorillas, and three chimpanzees, including an old male, Charly, who had bitten off part of Dressen’s right thumb, more than twenty years before. It also sheltered more than twenty tropical birds, Europe’s only captive colony of Gambian epauletted fruit bats, and several groups of exotic monkeys: silvery marmosets, white-faced sakis, and endangered golden-lion tamarins. These animals were among the zoo’s most cherished inhabitants. Some of the younger apes, such as a chimpanzee named Limbo, had been born at Krefeld, whereas the oldest, like Massa, a forty-eight-year-old silverback, had lived at the zoo longer than Dressen or any of his staff had worked there.

A thick fog slowed Dressen’s journey back to Krefeld, a midsize city, along the Rhine River, which has historically been the manufacturing hub for German silk and velvet. The zoo is near homes that Ludwig Mies van der Rohe had designed for industrialists nearly a century ago. It was four-thirty in the morning when Dressen arrived. He passed through a perimeter of armed police officers, which had formed around the ape house in case any panicked animals suddenly escaped through a collapsed wall or window. (Zoos have to put the safety of their visitors and personnel above all else; even when animals’ lives are threatened in a manmade disaster, it is necessary to treat the animals as part of the threat.) After extinguishing the roof, firefighters ascended a mobile platform and began looking for pockets of fire on the ground. They said that it was still too dangerous for anyone to search for survivors in the ruins. Dressen told his staff to get some rest and reconvene at eight. He went home himself, and had just taken off his shoes when he received a call: the firefighters on the platform had heard animal sounds in the rubble below.

Dressen returned to the ape house, but the firefighters said it would still be hours before zoo employees could search for the source of the sounds. So he went to his office, a room on the second floor of a little white farmhouse. There he kept—among books, sculptures, and fossils—an architectural model of the ape house. It included a large new outdoor area which he was planning for the chimpanzees. “Everything was finished,” Dressen said. “We had the money. We had the approval from the authorities. We wanted to start in July.” Dressen, who is sixty-three, has brown hair and a broad, friendly face. He favors practical clothes with the zoo’s logo and has the helpful manner of a knowledgeable gardener.

Few decisions are more satisfying for a zoo director than ones that improve the lives of the zoo’s animals and correct the shortcomings of the past. The Krefeld Zoo opened in 1938, during an era when zoos behaved in wanton ways. The old school of zoo directors were essentially animal collectors; they prized rare and exotic species and treated nature like a shopping catalogue. They hired traders to capture large wild animals as juveniles, often by murdering their mothers or entire social groups. Charly and Massa, and also a female chimp, Bally, and female gorilla, Boma, were all captured in the wild. They came to Krefeld in the nineteen-seventies, before collecting practices were reformed.

The animal trade ran through Germany for much of the nineteenth and twentieth centuries. Animals who survived their journeys were distributed from cities such as Hamburg to zoos in Europe and North America. They lived out their days in clusters of small and barren enclosures that gave visitors opportunities to see many related species in close proximity. Most zoos “were meant to help convey the gifts of biological literacy and enjoyable recreation,” William Conway, the former president of the Wildlife Conservation Society, once said, in a speech. “Saving wildlife was not much in the minds of their founders.”

In the second half of the twentieth century, as conservation awareness grew, administrators like Conway reinvented the zoo as a center of conservation education. They spent great sums of money to build more natural habitats, and used captive animals to raise awareness about and money for conservation. The cornerstone of the zoo’s transformation was collective breeding: instead of squeezing as much biodiversity as possible into their zoos, directors sought to create sustainable captive populations of the “A.B.C. animals” that were popular with the public—great apes, elephants, big cats, and the like. This required them to develop a complex system of animal exchange. Breeding priorities were set by centralized bureaucracies, such as the European Association of Zoos and Aquaria. Retooled and redeemed, zoos compared themselves to modern arks—havens where species could be protected from the destruction of the outside world.

In this new regime, a long-lived animal like Massa could be a source of both pride and shame. The Krefeld Zoo had bought Massa in 1975, when he was four years old, from an animal trader in Cameroon. Massa was aggressive and nervous in ways that made Dressen believe he had never quite recovered from the trauma of losing his family and his freedom. Massa would live long and father many children in captivity. The institution that imprisoned him had transformed around him. Still, many boundaries between the animal and the human, the natural and the artificial, were ineradicable. An indoor jungle could burn down like a common barn. Massa’s captive life would end as it likely had begun: in terror, gunfire, and tragedy.

Dressen came to Krefeld as a scientific adviser in 1992. He had previously volunteered at the Conservation and Research Center, in Front Royal, Virginia—the center of the Smithsonian’s captive-breeding program—and studied in Bielefeld and Zurich, where he met Heini Hediger, the founder of the field of zoo biology. In the nineteen-forties, when Hediger had begun his own career, he’d been dismayed by the amateurism of Swiss zoos. “The study of how to keep wild animals in zoos,” he complained, in 1950, consisted of “a collection of more or less disconnected pieces of advice and some facts.” Hediger began studying the lives of animals in the wild so that zoos could better meet their needs in captivity.

In a zoo, it would never be possible to give a captive tiger or polar bear the space that it would have had in nature. But zookeepers might still find creative ways to meet an animal’s social, reproductive, dietary, and physical needs. “If you make long-term observations, you can find out how animals behave in the wild, and transform this knowledge into the enclosure in the zoo,” Dressen told me. The ape house in Krefeld was one of the first zoo structures to incorporate Hediger’s principles. When it opened, in 1975, it wasn’t unusual for zoos to keep apes in empty tiled rooms that resembled public toilets. “It was common practice to protect their health in a sterile bubble,” the zoo architect Jon Coe told me. The result, Coe said, was often “an animal with increasing longevity that was also almost a mental vegetable. They lived with little sensory stimulation for forty years or more.”

The Krefeld ape house was a giant greenhouse. The acrylic glass panels on the roof allowed for high humidity and a stable temperature of around seventy-five degrees. A visitor to the ape house had the sensation of entering a jungle. Tropical plants grew, and birds flew between the exhibits for chimps, gorillas, and orangutans. People were separated from the animals not by glass or bars but by invisible trenches. The animals were given large climbing structures and private places where they could hide from prying eyes. The roof panels could be opened: on certain days, the animals could feel directly the heat of the sun or the splash of raindrops. In his history of the Berlin zoos, the German journalist J. W. Mohnhaupt wrote that the Krefeld ape house set “a new standard.”

When it came to fire safety, however, the architects had thought of only human needs. They had laid out evacuation routes and emergency exits for zoo guests but not the animals. Smoke detectors would likely not have worked properly with the ape house’s humidity, and were not legally required. Neither were sprinklers. If a fire broke out, the only way to rescue the animals would be to extinguish it quickly.

By the time Dressen began working at Krefeld, the ape house was seventeen years old, and even its innovative aspects were starting to look dated. Hediger’s principles had spread quickly throughout the zoo world, and other institutions had taken them further, building larger and more immersive exhibits with both indoor and outdoor areas. (Even in colder climates, most apes prefer to be outdoors in the spring, summer, and fall.) All the same, the Krefeld ape program was a success, and its animals were valuable contributors to Europe’s collective breeding programs. As a scientific adviser, Dressen helped Krefeld collaborate with other zoos to find breeding pairs. In 1997, twin chimpanzees were born in the Krefeld ape house—an exceedingly rare event.

That year, Dressen was checking on the newborns in the ape house’s “backstage” area when Charly, the alpha male, pulled Dressen’s hand through the bars and bit down onto his thumb. Charly only let go after Dressen removed his jacket and passed it to him through the bars. (Such injuries occur periodically among people who work with captive chimps: when I moved to Germany, in 2015, one of the first people I met was a former zoo director in Berlin who had lost an index finger to a chimp.) Soon afterward, Charly began throwing his feces at Dressen and taunting him with pant-hoots. The behavior continued for years, until Charly lost his alpha status to Limbo, one of the twins. Suddenly, Charly wanted to groom Dressen through the bars. “He was looking for coalitions,” Dressen said. “These chimps seek not only other chimps as coalition partners. They seek men, as well.”

Perhaps Charly was learning to respect the new boss: Dressen had been promoted to vice-director in 1996, and became full director in 2003. Under his leadership, the zoo transitioned from a department of the city to a nonprofit organization. He led the construction or renovation of exhibits for many of its animals, including tigers, black rhinos, meerkats, penguins, and tropical birds. “My main goal was for the zoo to become an educational institution for the conservation of animals and the protection of the environment,” Dressen said. He dearly wanted to upgrade the ape house, but learned that a whole new structure would cost more than twenty million euros. He decided that it would be better to build a new pavilion for the gorillas and add outdoor areas to the existing structure for the other apes.

The Krefeld Gorilla Garden opened in 2012. It included an outdoor space with a stream, hillocks, a termite mound, and a variety of herbs, and it brought visitors closer to the gorillas than ever before. When I first visited Krefeld, in 2017, Dressen showed me some metal grates that separated the animals from the visitors. “Can you smell it?” he asked. “We have these kind of special grate here, so you can smell the gorillas.” As we left, he gestured toward the ape house. “You can see, also, old and new side by side,” he said. Not all the animals got to enjoy the new space, however. Unlike chimpanzees, who live in mixed-male and mixed-female groups, gorillas live in what are termed harems, with several females but only one adult male. Massa, the old silverback, had become sterile in his advanced age, and the European Association of Zoos and Aquaria wanted Krefeld to keep a reproductive gorilla group. And so Massa stayed in the ape house with another gorilla, Bomo, while a new harem, led by Kidogo, a young silverback from a Danish zoo, occupied the garden.

Dressen’s next big project was to be an outdoor area for the chimpanzees. The architectural model in his office included a variety of climbing structures, nets, and plants. In order to prepare for construction, Dressen had sent five of Krefeld’s chimpanzees to other zoos; three chimps, Charly, Bally, and Limbo, stayed behind. The plan was that, when construction was complete, the animals would form the core of a new chimpanzee group. For the first time since they’d come to Krefeld, from Africa, in the seventies, Charly and Bally would feel grass beneath their feet.

More than fifty animals died in the Krefeld fire—more than have perished in a major zoo from a single event since aerial bombings during the Second World War.Photograph by Sascha Steinbach / EPA-EFE / Shutterstock

Before the fire, public visitors entered the ape house at its southwestern corner. They walked counterclockwise around the perimeter while looking inward at the animals. They passed the orangutans, then the gorillas, the chimpanzees, and, eventually, the saki monkeys. The backstage areas were at the center of the ape house, behind the enclosures and hidden from view. They contained smaller caged enclosures where the animals slept at night and received veterinary care. On New Year’s Eve, 2019, the animals retired not long after sundown. It was eight the next morning before the Krefeld fire department said that it was safe for zoo workers to check on them.

Dressen asked a veterinarian and an animal keeper to enter the enclosure. An armed police officer and the fire chief accompanied them. It was dark inside, and the team needed a flashlight to illuminate the path. They checked on the orangutans, who, unlike the chimpanzees and gorillas, were locked in their backstage enclosures at night, to separate a mother and child from a male as they slept. All five animals were motionless when the trio found them. Some of their hair had melted, and their skin was badly burned. Two orangutans showed faint signs of breathing, but were unresponsive. The team decided to move on before euthanizing them, in hopes of finding the animals that the firemen had heard.

In the gorilla section, Boma was dead in the sleeping area, but Massa had fled into the main enclosure. They found him in the rubble. He was slumped unconscious against a wall and had suffered severe burns. Despite his injuries, he was not yet dead. His rib cage pumped with very shallow breaths.

It was clear to the group that he hadn’t been the source of the sounds that the firefighters had heard. In the chimpanzee section, Charly was dead in his sleeping area. Bally and Limbo were nowhere to be seen. The keeper called the chimps’ names, and the group heard movements in the exhibition area. Soon, both apes appeared from behind the trees and climbing structures, with burns on their faces and hands. They walked up to the bars of their backstage enclosure, as though reporting to their regular morning veterinary exam. “We were completely surprised,” Dressen said. “I expected nobody survived, because if you’ve seen the pictures of the fire you cannot imagine that there is life inside.”

The fire had damaged a hydraulic door dividing the chimps’ main enclosure from the backstage area. It would need to be repaired before their rescue; otherwise, the animals would retreat and hide in the main enclosure as soon as they saw the veterinarian’s tranquilizer gun. Dressen contacted the man who had installed the door. Meanwhile, the veterinarian returned to the two orangutans and gave them lethal doses of anesthesia. She went to Massa next. She struggled to administer an injection and surmised that, because of his injuries, his circulatory system would not carry the poison to his heart. The veterinarian appealed to the police officer, who shot Massa several times.

In total, more than fifty animals died in the fire—more animals than have perished in a major zoo from a single event since aerial bombings during the Second World War. Along with the eight great apes, eleven monkeys died; so did all the birds and fruit bats, and also three rodents called acouchis. In recent history, the only comparable event occurred in 1995, when smoke from a small fire at the Philadelphia Zoo filled the air ducts of the ape house and asphyxiated twenty-three animals, including six gorillas and three orangutans. “In the last fifty years or so, there have only been a few accidents in which we have had to mourn the loss of a great ape—never a loss like Krefeld’s,” Maria Teresa Abelló, a curator at the Barcelona Zoo who supervises the great-ape-conservation programs for the European Association of Zoos and Aquaria, told me.

After the fire, Dressen contacted human pathologists. He wanted to know what the animals had experienced as they died. “One of the main questions was whether they suffered for a long time,” he said. The pathologists told him that, in all likelihood, the animals had fallen unconscious from smoke inhalation and died from asphyxiation. “This declaration gives us at least a little bit of consolation,” Dressen said. In the days after the fire, he organized two memorial ceremonies: one attended by zoo staff and volunteers, and another for city residents.

One of the surprising things about the fire was how quickly it had burned. Police believe that the sky lantern spilled its fuel on one of the roof’s acrylic-glass panels. The material is only moderately flammable, but the lantern fuel burned much more slowly than lighter fluid or gasoline. Within a few minutes, a hole melted through the panel, and the warm air inside the ape house rushed outward, igniting the panels and spreading the fire across the roof.

Such lanterns are illegal in Krefeld; the women who lit them turned themselves in as soon as they heard that they were the fire’s suspected cause. The women have remained anonymous, and eventually they each paid a fine. Dressen told me that he didn’t want to see them punished. “In German, we would say it’s a ‘Zusammenstoß verschiedener unglücklicher Ereignisse.’ ” He thought for a moment about an English translation. “A collision of unfortunate circumstances,” he said.

A month after the fire, Dressen drove me from his office to the ape house, which was surrounded by fences and construction equipment. There was not much left to see. The large rectangular building had been stripped to its steel frame and concrete foundation. It could have been a hangar or a warehouse.

In the quiet zoo, Dressen took me to the backstage area of the Gorilla Garden. At the bars, the enormous silverback Kidogo, who’d come to Krefeld from the Danish zoo, was waiting for snacks from his keeper. Kidogo had been born in captivity and raised with a father and older brothers as role models; he was a much gentler leader than Massa had been. The gorillas in the Gorilla Garden had been the luckiest great apes at Krefeld. Still, they had to make adjustments after the fire. Kidogo feared the large cranes that had appeared outside and was still adjusting to the sounds and smells of his new chimpanzee neighbors; he often kept his harem and children indoors, for protection. As a keeper spoon-fed Kidogo yogurt, Limbo, who wanted grapes from his keeper, threw a tantrum down the hallway, screaming and kicking his feet against the bars of his new backstage enclosure.

Bally, the other chimp survivor, watched patiently from a platform at the back of the enclosure as her companion acted out. Though she was forty-eight years old, Bally’s face and hands were covered in what Dressen called “fresh baby skin.” A chimpanzee’s skin darkens as it ages, but her brows, ears, and cheeks were pink where her burns had healed. “I don’t know if it will change back again,” Dressen said.

In the weeks after the fire, Dressen spent a lot of time explaining to insurance companies the unusual ways in which zoos operate. “Their main question was the value of the animals,” he said. He explained that zoos stopped assigning monetary value to their animals decades ago. They almost never buy or sell animals on the open market; instead, they exchange them with one another, based on the priorities of collective breeding.

The insurance companies wanted to replace the ape house with a similar structure. “I had to show them that the minimum standards now are quite different than the standards of 1975,” Dressen said. Over the past year, as the pandemic has unfolded, he has designed a memorial site, with a statue of a gorilla, that will be constructed near the old ape house. He’s also begun planning a new exhibit for the apes. It will be more than ten times larger than the old ape house, with outdoor areas and separate indoor facilities for each type of ape. When we looked together at the ruins, Dressen told me that he found the idea of building a new ape house without outdoor areas inconceivable. “I will not build up an ape house like this again,” Dressen said, his voice resolute. “I have now the chance to do it in a new way.”