Glass and other debris were swept out of the AquaDom building, which also contains a hotel and cafes, as water poured out of the 25m-high aquarium – believed to be the largest of its kind in the world - shortly before 6am local time.
Police spokesman Martin Stralau said at least one person was slightly injured by broken glass. It is also feared that most of the 1,500 fish kept in the aquarium will not survive in what has been described as "unbelievable marine damage”.
There was speculation that freezing temperatures contributed to the leak, however authorities said the cause of the incident is still being investigated. It is not believed that the explosion was caused by any kind of targeted attack.
Witness Gwendolin Szyszkowitz told German news channel n-tv that she heard a loud bang and initially feared a bomb had exploded.
Berlin's public transport authority said Karl-Liebknecht street outside the Radisson Collection hotel had been closed off due to "an extreme amount of water on the road".
Operators say the aquarium had the biggest cylindrical tank in the world and contained tropical fish of 80 different species before the incident. The aquarium, which was last modernised in 2020, is a major tourist attraction in Berlin and is situated near the city’s Alexanderplatz.
The 10-minute elevator ride through the tank was one of the highlights of the centre.