Approximately 60,000 residents of Germany’s financial capital, Frankfurt, will be ordered to evacuate their homes on Sunday as the city's emergency service staff will attempt to defuse a massive World War Two bomb, discovered recently at a local building site. The 1.4-tonne HC 4000 bomb dropped by the British air force during World War Two was uncovered on a building site on Wismarer Strasse in Frankfurt’s leafy Westend where many wealthy bankers live.

“We have never defused a bomb of this size,” bomb disposal expert Rene Bennert told Reuters, adding that it had been damaged on impact when it was dropped between 1943 and 1945.

Bomb disposal experts who examined it said the massive evacuation could wait until the weekend. “We are still working on the modalities of the evacuation plan,” a spokeswoman for Frankfurt police said on Wednesday.

As a result, ahead of Sunday's planned evacuation, more than 100 hospital patients, including premature infants and those in intensive care, were evacuated from two Frankfurt hospitals on Saturday, city councillor Markus Frank told Reuters television.

Every year more than 2,000 tonnes of live bombs and munitions are still found in Germany, even under buildings. In July, a kindergarten was evacuated after teachers discovered an unexploded World War Two bomb on a shelf among some toys. During World War II, Germany was pummeled by 1.5 million tonnes of bombs from British and American warplanes that killed 600,000 people. German officials estimate 15% of the bombs failed to explode, some burrowing six meters (yards) deep.

And while local residents have been eager to comply with the unprecedented evacuation, the biggest since the war, Frankfurt fire and police chiefs said they would use force and incarceration if necessary to clear the area of residents, warning that an uncontrolled explosion of the bomb would be big enough to flatten a city block.

Frankfurt’s residents have to clear the area by 8 a.m. on Sunday and police will ring every doorbell and use helicopters with heat-sensing cameras to make sure nobody is left behind before they start diffusing the bomb.

Where this otherwise trivial evacuation takes on a more sinister, "Die Harder" spin, is when looking at what other structures are impacted by the 1.5 km evacuation radius: these include Frankfurt’s Goethe University, police headquarters, two hospitals, transport systems... oh and the Bundesbank headquarters, which as a reminder ten days ago completed the accelerated repatriation of 674 tonnes of gold - some three years ahead of schedule - from New York and Paris to its vault deep underground.

According to Reuters, the Bundesbank vault which stores 1,710 tonnes of gold deep underground - approximately half the country’s reserves - is located less than 600 meters from the location of the bomb. Well, that particular vault which now holds $70 billion in gold (including $28 billion in freshly repatriated physical) and everything around it, is about to be evacuated. All that's missing are several dozen dump trucks to take advantage of the massive evacuation that will leave thousands of gold bars without security for 1.5 kilometers in any direction.

While airspace for 1.5 kilometers around the bomb site will be closed, we doubt that will prove a major hurdle to anyone eager to take a stab at a real-life reincarnation of the second Die Hard movie.

Still, to prevent anyone from getting any ideas of following in Simon Gruber's footsteps, a spokesman for the German Bundesbank said, that "the usual security arrangements" would remain in place while experts worked to disarm the bomb.

The fate of half of Germany's gold aside, bomb disposal experts said they will make use of a “Rocket Wrench” to try and unscrew the fuses attached to the HC 4,000 bomb. If that fails, a water jet will be used to cut the fuses away from the bomb, Bennert told Reuters. The most dangerous part of the exercise will be applying the wrench, Bennert said.

Roads and transport systems, including the underground, will be closed during the work and for at least two hours after the bomb is defused, to allow patients to be transported back to hospitals without traffic. It is not unusual for unexploded bombs from World War Two air raids to be found in German cities, but rarely are they so large and in such a sensitive position.

Meanwhile, Frankfurters can spend the day at shelters set up at the trade fair and the Jahrhunderthalle convention center. Most museums are offering residents free entry on Sunday, and a few of them will open their doors earlier in the morning than usual.