Cleanup efforts were underway on Saturday after a massive aquarium at a hotel in the German capital burst.

Two people sustained injuries in the disaster at the Radisson Blu complex, which housed so-called Aquadom.

The popular tourist attraction was hailed as "the world's largest freestanding cylindrical aquarium," leaving many to wonder what happened to its aquatic inhabitants.

How many fish survived?

There were an estimated 1,500 tropical fish living in the aquarium at the time it burst.

Out of those, most of the fish in the tank died. Hotel guests reported seeing many dead fish on the ground and among the rubble in the hotel. Other dead fish were found in the streets of Berlin in front of the hotel.

Saltwater fish can only survive for an hour or two out, NTV reported. Their gills begin to dry out and they are unable to take in oxygen, meaning they eventually suffocated.

Frigid winter temperatures on Friday also drastically lowered the chances of survival. At the time of the incident, which saw water and debris bursting from the front of the hotel, the temperatures in Berlin were -7 degrees Celsius (19.4 degrees Fahrenheit).

A few, however, survived.

Berlin's Fire Department said that some of the fish had survived in puddles that resulted from the destruction of the 1 million liter tank (264,000 gallons).

"Several dozen" were found alive in the remains of the tank, the Fire Department said on Twitter.

Between 400 and 500 smaller fish that were located in breeding tanks in the basement of the hotel also survived. They had to be rescued and relocated, however, as the electricity to the building was cut due to safety reasons.

Freshwater fish that were rescued were taken to the Berlin Zoo, while the saltwater fish were taken to Sea Life, an aquarium chain that also has a location in Berlin.

The Sea Life aquarium is located in the same building complex as the Radison Blu Hotel where the AquaDom was located. Sea Life, however, did not report any damage.

Why did the tank burst?

Early on Friday morning, the massive glass tank inside the Radisson Blu hotel complex burst.

The destruction of the 16-meter (52-foot) high aquarium sent a wall of water, fish, glass and debris pouring into the hotel lobby and out into the streets of the German capital.

At the time of the disaster, most of the hotel's guests were not located in the lobby, leaving only two people with injuries from the shattered glass.

Cleanup efforts continued on Saturday, with investigators now focusing on what caused the tank to break.

Authorities on Friday said they do not believe the disaster was caused by a criminal act and the cause was not immediately clear.

Berlin Mayor Fraziska Giffey noted that the tank had "just recently been renovated."

Other officials said, however, that initial investigations point to potential issues with the building materials in the 18-year-old tank.

"Investigators into the cause [of the incident] are of course not completed, but initial indications point to material component fatigue," Iris Spranger, Berlin's state interior minister, told news agency dpa.

rs/jcg (dpa, AFP)