The date March 21 1973 is etched into the memory of ex-miner Tony Banks.
He was working the night shift 750 feet below ground at Lofthouse colliery, near Wakefield in Yorkshire.
The pit had six coal faces. One broke through into an abandoned and water-filled Victorian mine shaft. Millions of gallons of rubble-bearing water smashed through the coal face, carrying all before it.
The face was at the end of a roadway more than three miles from the pit bottom, where miners are lowered and raised into and out of the pit.
Miners fled the inrush of water. Tony, an overman, was on a different face. He escaped as the 1,000-man pit was evacuated.
When heads were counted seven men were missing. A rescue operation began, drawing in specialist teams from coal mines around the country. I was on the spot, reporting from the pithead.
For six days valiant mines rescue crews battled to get through the floodwater and wreckage, behind which it was hoped the men just might have found refuge in an air-pocket.
It was in vain. Even frogmen could not get through.
One battered body, hurled hundreds of yards by the flood, was recovered. The other six could never be reached.
A monument to the men stands by a roadside, in a memorial garden more than three miles from the old pithead, above the spot where the men's bodies are believed to be entombed.
On Saturday and Sunday this week ex-miners from Lofthouse, their families and friends will stage a commemoration of the 40th anniversary of the Lofthouse Colliery Disaster and the deaths of their seven comrades - face workers Frederick William Armitage, 41, Colin Barnaby, 36, Frank Billingham, 48, Sydney Brown, 36, Charles Cotton, 49, Alan Haigh, 30, and pit deputy Edward Finnegan, 40.
Tony, now 70, is one of the organisers of the commemoration, which will also be a reunion for the miners and families of Lofthouse, which shut in 1982.
His memories of the disaster are crystal clear.
"About 2.20am there was a sudden surge of wind and it knocked us off balance," he says. "I had a phone call from the pit top calling for an electrician to the 59 drift (the face hit by the inrush of water) because they'd lost all contact by phone.
"Then I was told there'd been an inrush of water and 14 men were missing, and we had to get out of the pit."
He also recalls that but for circumstance, some of the seven men who died would not have been there.
Three were either standing in for others who had asked for the night off - one was on his honeymoon - or had requested to work the shift for their own reasons.
"Charlie Cotton was going to be 50 the next day," Tony tells me. "He asked to work that night so he could have the day off. He went in with his son Terry."
Tony said when the inrush came Charlie shouted to his son: "Run! And look after the kids!"
"Charlie was killed. Terry got out," Tony says.
For the six days of the attempted rescue operations, anxious families gathered at the pit-head. Crowds watched for the pithead wheels beginning to turn, a sign that maybe somebody had been found. It was not to be.
When the rescue mission was abandoned, a fund was established to help the families of the men who died. Money came in from across Britain and beyond.
The fund still operates today.
"There's only one person left, Mrs Brown, whose husband was killed," says Tony. "The Browns lived in Leeds. She's the only surviving dependent. Mrs Cotton, Charlie's widow, died last year."
A public inquiry was held into the disaster. Arthur Scargill, then in his 30s, performed brilliantly as advocate for the National Union of Mineworkers.
The inquiry decided that the seven men had died instantly.
It also decided that if the National Coal Board - which knew of the existence of abandoned Victorian shafts scattered across the coalfield - had carried out thorough research into their location, depth and condition, the tragedy might have been avoided. New regulations governing the opening of new coal faces were introduced.
After Lofthouse closed in 1982, its miners were scattered around other Yorkshire pits.
Tony ended up at Wistow, one of five pits sunk in the £1 billion Selby coalfield development.
On Saturday he'll be reunited with his old Lofthouse comrades at the memorial events. Though the pit has gone, its union banner survives and will be brought out with pride from its nearby home, Outwood Memorial Hall. It will be joined by other NUM banners.
The commemoration includes a service at the memorial monument above the men's entombment, a church service and a social event, complete with brass band, at Leger Lane Club at 2pm on Saturday.
At the time of the Lofthouse Colliery Disaster there were around 250 deep coal mines in Britain. Today there are three. But still the deaths continue. In recent years three men have died in accidents at Yorkshire's Kellingley colliery.
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