"The sound of falling ice developed into an almighty roar. It came crashing down.

"It all happened in a flash. I could not believe my eyes."

Engineer Alan Redgrove, 27, had been on duty for just half an hour when the 1,264ft Emley Moor mast , known as the ITA Tower, fell at 5.01pm on Wednesday March 19, 1969.

He was working with engineer-in-charge Ian Lambe, who said he had been on the telephone in his office. The following day he told the Examiner: "It was like thunder.

"We did not really believe it. It was difficult to see through the fog."

The Examiner reported the noise of the mast smashing to the ground could be heard from miles around.

People rushed from afar, knowing something disastrous had occurred - but because of the thick fog they could not see that the mast had fallen.

Control room staff could not be sure nobody was in a building at the base of the tower, which had been completely crushed. Just five minutes earlier, six men had been working there. Only the day before, the building had been handed over to the television authority for colour transmitting equipment to be installed.

The mast crashed through Emley Moor Methodist Church and onto the road nearby - and in some places the huge steel tubes had buried themselves five feet into the surface of the road.

Clr Silverwood Burt, 68, and church caretaker, miner Jeffrey Jessop, 42, were in the church inspecting the roof, which was full of gaping holes from previous ice falls from the mast - for every 6ft of cable there was a hundredweight of ice.

Clr Burt was wearing a crash helmet which he put on whenever he went near the mast. He said he heard a loud rumble, before the church roof caved in on top of him.

He said: "The crash helmet saved my head. I don't know what we shall do now. All the roof has collapsed and the organ and piano have been smashed. It was just like a volcano erupting."

Mr Jessop, who escaped injury apart from a small cut to his hand, said: "I have never known anything like it down the pit. I heard a thump from above and thought it was a lump of ice. But then the cables appeared through the roof, so I dived straight across the room and under some seats."

His wife Janie said: "I knew he was in the church and I was terrified until he called out to me. Nobody could see what was happening through the fog.

Neighbours Mr and Mrs George Oakley said they had rushed outside after hearing rumbling. Mrs Oakley said she hadn't slept for a week after hearing ice fall from the mast - but she added: "I won't be troubled by the noise tonight."

Work went on through the night to clear the road and make sure nobody was trapped, as West Yorkshire Police dealt with crowds of spectators who gathered at the scene.

Debris lay in fields around the area, but the fibreglass top was found 200 yards away, just a few yards from a row of cottages.

Investigations revealed the mast folded during its descent, falling towards the church before the top began to veer back in the other direction.

Later, Emley villagers told the Examiner they didn't want another mast at the site. Jeffrey Jessop said: "We are not having another mast built here if I can help it. It is about time more thought was given to people and property. Unfortunately, I don't think there is much we can do to stop another mast being built. Clr Burt said villagers wanted any new mast to be rebuilt further into the fields.

Building work on the current tower started in 1970, and colour transmissions began on January 21, 1971.

Today the Grade II listed Arqiva Tower it is one of Yorkshire's most recognisable and best loved landmarks. It is the UK's tallest freestanding structure at 1,084ft (330m) - and it takes seven minutes to get to the top!