A massive aquarium holding 1,500 tropical fish bursts in Berlin

The enormous cylindrical aquarium was a wonder, the centerpiece of a popular Berlin hotel. But in the early hours of Friday morning, it burst — and soon afterward, Berlin Mayor Franziska Giffey said all of the roughly 1,500 fish the aquarium had contained were believed to be dead. Reports later emerged that workers might have been able to rescue some of the animals.

The AquaDom aquarium was touted as the largest freestanding cylindrical aquarium in the world. The aquarium dominated the large atrium of the Radisson Collection Hotel — where the mass of water blew parts of the hotel's façade into the road and left the building badly damaged, the Berlin fire brigade said.

The catastrophic rupture of the AquaDom aquarium took place around 5:45 a.m. local time, sending 1 million liters (more than a quarter of a million gallons) of salt water — and fish — pouring into the hotel's atrium and lobby and out into the street, as dozens of emergency response workers raced to the scene.

Berlin Police say two people were hurt, the result of glass shards. They also say there are no signs of a crime.

The building's owner says the AquaDom aquarium was completely destroyed, and that the cause is not yet known. The hotel is now closed because of the damage, Radisson says, adding that all guests are being relocated.

People who were staying in the hotel report being awoken by a loud crash or rumbling noise, only to realize that the immense fish tank was suddenly gone. Witnesses say the calamity left dead fish, ruined furniture and debris strewn around the hotel's atrium, according to Deutsche Welle.

There are reports that some of the fish might have been able to endure their habitat's sudden collapse, saved by small pools of water from the deluge. German public broadcaster RBB reports that some fish were apparently found near an elevator and taken to a tank in the Sea Life Berlin facility in the same complex — but it notes that those and other animals were also in peril, because the power was knocked out to that part of the building.

If the water carried them outside, any surviving animals would immediately struggle to survive the cold, as temperatures in Berlin were well below freezing. While the water in the fishes' tank was kept around 79 degrees, Friday's high was forecast to hit just 29 degrees Fahrenheit.

The large aquarium and hotel are part of the DomAquaree building, a complex that sits near the Berlin Cathedral. A clear-sided elevator traveled through its center, and visitors could sit beneath the mammoth aquarium in a bar and cafe area.

The aquarium's tragic failure comes months after it reopened over the summer, after being shut down for modernization work in October of 2019, according to its website.

Speaking at the scene shortly after the aquarium collapsed, Berlin Mayor Franziska Giffey said that if the disaster had occurred just one hour later, when more people were on the move at the hotel in the bustling Mitte district, the toll might have been even worse.

In another response to the sad news, Dan Ashe, president and CEO of the Association of Zoos and Aquariums, said in a statement sent to NPR that his organization is "shocked and saddened" by the catastrophe.

"Our hearts go out to the people and aquarium animals who have suffered," Ashe said. "And we extend our best wishes to the aquarium staff, who must be devastated."