It could have blown up Bramall Lane, killed hundreds and devastated Sheffield ... twice.
As it was, the massive German bomb failed to detonate during the war and was finally defused on February 10, 1985.
It did cause plenty of disruption though, with 330 people evacuated from their homes and Sheffield United’s match against Oldham postponed after the discovery by workmen.
The 2,200lb German device was one of three dropped in the Lancing Road area on the night of the Blitz, December 12, 1940.
It lay undiscovered for 45 years and then caused havoc for Highfield residents as the size of the bomb gradually dawned on experts.
It was initially estimated to be a 500lb bomb until excavations revealed the enormous truth.
The police cordon was extended, more folk cleared from their homes and scores of extra emergency service personnel put on standby.
That went on for two days as experts drilled gently through the fuse casing and removed it.
Community spirit came back to the fore and the doors of the Duchess Road community centre were thrown open for those with nowhere else to go.
Unfortunately, it was the second time some families in the area had pitched up there – it was also used for those who lost their homes during World War II.
Arnold Cosgrove lived with his wife Nellie on Edmund Road during both experiences: “We were evacuated then, so this is the second time. It’s a disturbance we don’t want at this time of life.
“I slept in this building in the Second World War when we were evacuated. We have had to make a number of phone calls to get fixed up for the night. We’d rather be in our own home.”
Mary Wright ended up sleeping at Duchess Road School, the same school where she had studied as a young girl in the early 1930s.
She said: “I heard about the bomb early afternoon but the police didn’t evacuate me until 8pm when they found out it was bigger than first thought. I was just getting settled for the night in front of the telly.
“I remember the Blitz. When they sounded the all- clear the whole area was devastated. We were some of the lucky ones.”
Constance Brightmore, who had lived in Shoreham for 70 years, also remembered the Blitz and didn’t mince her words.
“I don’t think much of this. When I heard, I could have died.”
The bomb was fondly nicknamed Herman the German but only after it had been made safe.
It was immediately whisked down to the Kent base of the army UXB squad which had defused it, and was visited by Prince Charles before being returned to Sheffield.
The bomb is on display at Kelham Island Museum – a permanent reminder of what the city faced, twice over.
At the time of its discovery, public surveyor in the council’s public safety unit said: “The bomb in Lancing Road could have gone off at any time. It was full of explosives and the devastation would have been dramatic.
“Not only would it have taken the roof off the stands at Bramall Lane – it would have taken a lot of lives and brought disaster to Sheffield.”
n See Saturday’s Retro for more photos of the Herman evacuees from 1984