A WWII bomb discovered in Poland detonated underwater on Tuesday while Polish navy divers were disarming it. "Tallboy" was the largest unexploded World War II bomb in Poland. 

Over 750 people had been evacuated from the area nearby Piast Canal outside Swinoujscie, where the WWII bomb used by Britain's Royal Air Force (RAF) was discovered, reported MSN.

The bomb was dropped by Royal Air Force Avro Lancaster in 1945 amid the raid on the German cruiser Lutzow. The WWII bomb detonated on Oct. 13, 2020, with no reported injuries from the eruption.

The Polish navy divers were attempting to make the device safe. The device has the capacity of initiating a small earthquake. It was detected in September 2019 at the bottom of a Swinoujscie shipping channel on the Baltic coast, reported Euronews.

Tallboy's Weight

The WWII bomb weighed almost 5,400-kg with 2,400-kg of explosives.

"The deflagration process turned into detonation. The object can be considered as neutralised, it will not pose any more threat," according to Second-Lieutenant Grzegorz Lewandowski, the spokesperson of the 8th Coastal Defense Flotilla, reported Times Now News.

The navy demolition experts were making efforts to neutralize it underwater through remote combustion burning. However, the WWII bomb went off in the process.

No Injuries

All the sappers were at a safe distance from the blast, which explained why it resulted in no injuries. "The operation was carried out perfectly and safely, and the bomb is safe now," according to Lewandowski, reported EveningStandard.

Also Read: 75 Years After World War II, 1 Million Japanese Soldiers Remain Missing

50-50 Risk of Detonation

The probability that the bomb at the bottom of a Baltic Sea shipping canal would explode was surmised to be 50 percent.

There were stunned reactions to the recent detonation that was reportedly felt in some areas of the city. A video showed the explosion throwing up a large column of water into the air.

The mine divers were not in the danger zone. Swinoujscie consists of a liquefied natural gas (LNG) terminal, but according to a spokesperson for the town's mayor, no infrastructure had been damaged.

Lewandowski noted it was the largest of such operation in Poland where undetonated wartime bombs, grenades, and missiles remain to be found.

The WWII bomb was designed by aeronautical engineer Barnes Wallis from the United Kingdom. It was used by the RAF to demolish large Nazi-controlled assets. Apart from Tallboy, it also had the moniker of an "earthquake bomb."

At the time of the bombardment, Swinoujscie was part of Germany and was named Swinemunde.

The naval forces used a remote-controlled device to attempt to deflagrate the WWII bomb. If successful, the process burns the explosive charge without resulting in detonation.

On Poland's border with Germany, the Piast Canal links the Baltic Sea with the Oder River. The bomb was detected beneath the Szczecin-Swinoujscie shipping channel, a waterway leading to the port of Szczecin. It was discovered during work to deepen the passage.

Related Article: World War II Bomb Caused Panic in Soho's Dean Street London