The RAF despatched 247 Lancaster bombers and 22 Mosquitos to destroy a freight yard at Porte de la Chapelle on the night of April 20.
In one of the heaviest wartime bombardments in France, they dropped some 2,000 bombs, mainly targeting the rail network and supply lines. Up to 670 people were killed, including civilians, and hundreds wounded.
Many of those forced to abandon their homes on Sunday were accommodated in gyms and community halls. Some Parisians were annoyed and said the authorities could have waited until the holiday period when many people would be away.
There were tense scenes before dawn as Civil Protection officers knocked on the doors of apartment blocks to alert people to the danger of disobeying the order to leave their homes. They were followed by police to reinforce the message. By 8:30 am, the entire neighbourhood was deserted.
Mr Delpuech said he regretted the inconvenience but the priority was to keep the public safe. He said the decision to detonate the bomb was only taken after attempts to defuse it failed. “This was an unprecedented evacuation, but it’s been a successful operation,” he said.
Unexploded ordnance from the Second World War is often discovered in France, usually by builders or farmers, but it is rare to find an unexploded bomb in the heart of Paris.