On October 13 the largest WWII bomb ever found in Poland, a “Tallboy” weighing more than five tons, accidentally exploded while demolition experts attempted to deflagrate the bomb—a process which burns the explosive charge without causing a detonation, Adam Easton of the BBC reports.

A navy spokesperson, Lt. Col. Grzegorz Lewandowski, told the Associated Press that no one was injured in the blast and that “the operation was carried out perfectly and safely and the bomb is safe now.”

The Tallboy, or “earthquake” bomb was found in September of last year during the drudging of the canal outside the port city of Swinoujscie, Poland—formerly part of Germany and called Swinemünde at the time of the bombardment. More than 750 residents evacuated from the surrounding area as navy sappers attempted to diffuse the bomb.

Embedded nearly 40 feet deep with only its nose sticking up through the muck of the canal floor, nearly half of the 19-foot-long Tallboy contained explosives.

Invented by British aeronautical engineer Barnes Wallis, creator of the “Dambuster” and “Grand Slam” bombs, this particular Tallboy was likely dropped by a British Lancaster during an April 1945 bomb raid which sank the German cruiser Lützow.

“The Tallboy was a seismic, deep-penetration bomb, designed to fall near a target and destroy it by exploding with a massive shockwave,” writes the BBC. It was previously considered too large for a controlled explosion for fear of the damage it could cause to the city and its people.

While the unexpected blast was felt by local residents, “the object can be considered neutralized, it will not pose any more threat to the Szczecin-Swinoujscie shipping channel,” said Lt. Col. Lewandowski.

Watch the stunning scene below: