German authorities are making final preparations in Frankfurt before experts defuse a huge World War II-era bomb Sunday in an operation that includes evacuating more than 60,000 residents.

Hospital patients and the elderly are among those affected in what will be Germany's biggest evacuation in recent history.

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

Dozens of ambulances lined up before driving to pick up anyone unable to independently leave the danger zone.

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.