Technicians worked for hours Sunday to successfully defuse a World War II-era bomb that had been lying dormant under the bustling streets of Frankfurt for some seven decades.

The 4,000 pound bomb was discovered Tuesday at a construction site for Goethe University faculty buildings, reports The New York Times. It is believed to have been dropped by the British Royal Air Force.

Everybody within a mile radius of the bomb had to leave Sunday morning, leading to an evacuation of more than 60,000 people.

The BBC says it was the largest evacuation in Germany since the end of World War II. Experts warned that if the bomb accidentally went off, it would be powerful enough to flatten an entire street.

There were no exceptions to the rule: everybody had to clear out, including those inside hospitals, nursing homes and Germany's central bank.

Premature babies and ICU patients were among those who got out, says the BBC.

For those who opted not to go far, the city opened its convention center and museums offered free entry.

Police used a heat-sensitive camera to ensure nobody remained before experts went to work defusing the 2-ton bomb, reports The Times.

It was a job that has been done many times over; on average about 2,000 tons of unexploded ordnance are found every year across the country, reports the BBC. Every couple of weeks, Germany's bomb-disposal unit disables a bomb and says the work should last for years to come.

There are believed to still be hundreds of thousands of unexploded bombs dropped during WW II remaining throughout Germany.

The Two-Way reported in May that 50,000 people had to evacuate the German city of Hanover while experts defused three British bombs.

Millions of tons of bombs were dropped over the course of the war, many of which never went off.And so, cities were rebuilt and life went on over ordnance that is still able to wreak havoc.About a dozen bomb technicians have been killed in Germany since 2000, reports Smithsonian Magazine. And the danger may be getting worse.(NPR's) Soraya (Sarhaddi Nelson) says, "Undetonated World War II bombs, of which there are thousands still buried around Germany, are becoming more dangerous with time because of components breaking down."

Just a day before Frankfurt's evacuation, around 21,000 residents had to leave their homes in the western city of Koblenz, while a 1,100-pound American bomb was defused.

Frankfurt Police called the bomb defused Sunday, "the defeated beast" and tweetedimages of it being loaded onto a truck and driven away.

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