BERLIN — A relic of the relentless pummeling that flattened much of Germany more than 70 years ago forced tens of thousands of people to temporarily abandon their homes on Sunday in Frankfurt.

Technicians worked for hours to defuse a 4,000-pound, World War II-era bomb, thought to have been dropped by the British Royal Air Force, after it was discovered on Tuesday at a construction site for faculty buildings on the edge of Goethe University.

More than 60,000 people living within about a mile of the bomb cleared out early Sunday from a well-to-do district that is home to some of Frankfurt’s banking elite, as well as Germany’s central bank, a day after two hospitals and several retirement homes were evacuated.