FRANKFURT, Germany -- Police say bomb disposal experts have successfully defused a massive World War II-era bomb in the German financial capital Frankfurt that forced the evacuation of more than 60,000 residents.

Hospital patients and the elderly were among those affected in what was Germany's biggest evacuation in recent history. Similar operations are still common 72 years after the war ended. About 20,000 people were evacuated from the western city of Koblenz before specialists disarmed a 500-kilogram U.S. bomb Saturday.

Construction workers found the 1.8-ton -- 4,000-pound -- British bomb Tuesday. Officials ordered residents to evacuate homes within a 1.5-kilometer, nearly a mile, radius of the site in Germany's financial capital.

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Dozens of ambulances lined up early Sunday to pick up anyone unable to independently leave the danger zone.

In another case, a kindergarten was evacuated last month after a teacher discovered an unexploded World War II-era bomb on a shelf, BBC News reports. A child had brought it inside after finding it while on a walk, police said.