World’s biggest free-standing cylindrical aquarium bursts in Berlin

"A million liters of water and all the fish inside spilled onto the ground floor," a spokesman for the Berlin fire department added.

The incident happened at around 5:45 am local time (0445 GMT). Residents heard a very loud noise and saw parts of the facade of the hotel flying into the street. 

The tank in our hotel….blew? #berlin #radisson #hotel #aquarium pic.twitter.com/4pfheKSc4G

— Larissa (@lararimmer) December 16, 2022

Meanwhile, mayor Franziska Giffey said the incident had unleashed a "veritable tsunami" of water, but because it was so early in the morning, it had prevented more injuries from occurring.

"Despite all the destruction, we were still very lucky," she said. "We would have had terrible human damage" had the aquarium burst even an hour later, she explained.

This is because since most residents were still sleeping, they were not in the area of the accident.

The aquarium, called the AquaDom, housed 1,500 fish. It was described as the biggest cylindrical tank in the world.

Desperately trying to save the fish

Efforts were underway Friday afternoon to save approximately 400 to 500 fish housed in aquariums underneath the hotel lobby. Because electricity had been affected by the incident, their tanks were not receiving the necessary oxygen for them to survive.

Various organizations, most notably the Berlin Zoo, offered to take in any surviving fish. It is unclear at the moment how many have been saved.

The aquarium was filled with one million liters of salt water, equating to 1,000 cubic meters of water weighing 1,000 metric tons, and was a very popular tourist attraction. It even had an elevator.

Police at the moment say there is no evidence the damage was from an attack. It is instead speculated that freezing temperatures that got down to minus 10 degrees Celsius (14 degrees Fahrenheit) overnight caused a crack in the acrylic glass tank. The weight of the water then caused an explosion.

The incident also saw so much water leaking onto the adjoining Karl Liebknecht Street that it forced the partial closure of the major traffic artery. Tram service had to be suspended.