They vanished in clouds of dust along with the giant gasometers emblazoned with the name of "Ravenscraig" as men watched stoney faced and women wept tears of sorrow.
Thousands of onlookers were there on that fateful day – Wednesday, July 31, 1996 – to watch the demolition of their beloved 'Craig', which had fallen silent four years earlier.
The demolition team did its job well.
So had the steelmen of Motherwell who had made the Craig the most cost effective site in the UK.
But their reward was mass redundancy.
Tory Prime Minister Margaret Thatcher and Ian MacGregor, the controversial Canadian she had put in charge of the British Steel Corporation, were cast as the villains.
Thatcherism was all to do with market forces and nothing to do with State subsidies.
There was a global recession and a slump in demand for the steel made at Ravenscraig. Mr MacGregor decided to shut down one of Britain's five steel making centres.
Motherwell was singled out for the axe. It was ruled to be too far away from the market place.
Opposition politicians and union leaders were outraged and mounted a public campaign of opposition.
Senior Scottish Tories were also appalled. They recognised the political and social consequences of any closure and fought hard to have the closure delayed.
Downing Street and British Steel stood firm and ignored the public pleas, the reasoned arguments and the protest petitions and on June 24, 1996, the last batch of steel was produced at the Craig.
More than 700 men walked out of the gates for the last time.
The town fell silent. No more screeching sirens to signal the start of shifts – 6am for the day shift, 2pm for the back and 10pm for the night shift.
No more red skies from the glowing furnaces.
It had been a slow, slow death for the Craig.
Six years earlier Gartcosh had been shut down, and that sounded the alarm bell for Craig works convener Tommy Brennan because it finished off a lot of steel slabs from Ravenscraig.
Tommy said: "Gartcosh gave added value to our products, so we knew it would make our survival much more difficult, but not impossible.
"We still had a strong economic argument. The Japanese measured efficiency by equating man hours with production levels. We were operating at two-and-a-half to three man hours per tonne compared to the UK average of 6.2 man hours per tonne, and we completed 90% to 94% of orders on time, which, was astonishing."
But British Steel had invested tens of millions of pounds in rival plants and there were real fears that Motherwell would be the victim of cost cuts. Management knew any attempt to shut Ravenscraig would need to be justified. They introduced contentious production clauses and selective ordering – all favouring steel plants in Wales.
It was three years after Gartcosh fell silent when Tommy warned his fellow stewards that they faced a fight to the death. It took another three years before the heart beat of Motherwell was silenced. By then John Major was Prime Minister and Bob Scholey was chief executive at British Steel.
Two decades on and 79-year-old Tommy is still angry. "We could make gold bonds but they were hell bent on closing us down," he says. "It wasn't Thatcher, although a lot of people blame her, and it wasn't really Ian MacGregor. I blame Bob Scholey – he didn't like the Scots. He never did."
Union leaders fought hard to keep the plant alive and even suggested mothballing it until global demand picked up. Their pleas fell on deaf ears.
Twenty years on, and with new college and sports centre on the old Ravenscraig site, Tommy says: "We're feeding the mind and exercising the body but so much more has to be done."
Ravenscraig opened in 1957, after Harold Macmillan agreed to lead the Tory government and the country when Sir Anthony Eden resigned as prime minister following the Suez Crisis.
Almost immediately there were demands for a strip mill at the site. Owners, Colvilles, pushed hard, realising that steel from the mill could be sent by road to the ailing Gartcosh works 14 miles away where it could be transformed into sheet steel.
The move would protect Gartcosh, even though it wasn't part of Colvilles.
The government also persuaded motor manufacturer Rootes to build a car plant at Linwood, Renfrewshire, with the promise of grant money. The cash ploy was also used to persuade Leyland to open a truck plant at Bathgate in West Lothian.
Colvilles agreed to build the strip mill with a government loan of £50 million.
The government then decided two mills should be built – one at Motherwell and one at Llanwern in South Wales, and both would be only half the size of what had originally been planned
Winter was on its way when the hot strip mill began operating in the weeks before Christmas, 1962.
The multi-million pound addition made Ravenscraig the most modern steel plant in the UK, but relations between the workers and bosses were still stuck in the Dark Ages.
Dozens of strikes blighted the site.
Harold Wilson moved into 10 Downing Street in May, 1964, after Labour ousted the Tories, and in the following four months management at the Craig had to deal with more than 30 stoppages.
Colvilles introduced a new plan to try to minimise disputes, while Wilson and his Cabinet announced their plans to bring the steel industry back into State ownership.
But another change of government brought a change of policies. Mrs Thatcher resented the use of public money to prop up nationalised industries.
She believed market forces should dictate whether businesses lived or died.
Heavy industry went into rapid decline while she was prime minister.
Car production at Linwood ended in 1981, truck manufacturing at Bathgate halted four years later. Both plants were major customers for the steel made at the Craig.
Workers at Gartcosh were thrown on to the dole when the mill was axed in 1986.
Six years later steelmaking ended at Ravenscraig.
In a twist of fate, just two days later Mrs Thatcher was given the title of Baroness Thatcher of Kesteven, which saw her step back from frontline politics and leave the Commons for a seat in the House of Lords.
SIX seconds. That's all it took to turn back the clock by almost 40 years and forever change the skyline at Motherwell. This week, to mark the 20th anniversary of the closure of Ravenscraig, GORDON THOMSON looks at the changes it brought about.