FRANKFURT, GERMANY — Explosives experts in Frankfurt on Sunday defused a massive bomb — a remnant of the last World War more than 70 years ago.

CNN reports that the 1.4 ton HC 4000 bomb was found buried at a construction site close to Goethe University's Frankfurt campus on Tuesday.

The discovery prompted authorities to cordon off a 1.5-kilometer radius danger zone around the explosive. Over 60,000 people were evacuated from the area, which was home to hospitals, retirement homes, and the Bundesbank, Germany's central bank.

Dubbed 'Blockbuster', the British World War II-era bomb could reportedly generate an explosion capable of flattening an entire block.

Of the estimated 1.5 million tons of munitions dropped on Germany by Allied forces, some 15% failed to explode and ended up getting buried, according to the New York Times. Experts say over 2,000 tons of unexploded weaponry are found in the country each year.

Despite having a dedicated bomb-disposal unit, Germany's unexploded bombs remain a problem. The aging munitions could become more brittle and unstable, and are reportedly being spotted in harder-to-reach areas, reports the BBC.