IT numbed Bolton and horrified a Britain where the club culture was just starting to be king in those Swinging Sixties.

But exactly why 19 people died at the Top Storey Club has never been discovered.

And today, 40 years on, although there were allegations of arson at the time, the authorities are no nearer finding the cause of the worst peacetime fire tragedy ever to hit the borough.

The club's name has passed into the local vocabulary of those old enough to remember the shock waves of what happened on that evening of Monday, May 1, 1961.

But the real legacy lives on in the massive change in the laws governing safety in clubs, licensed premises and entertainment venues that followed the national outcry over the Bolton club.

Today there is now no chance of a Top Storey Club being opened anywhere in the land, including Bolton. Controls are simply too tight.

It was, as the name suggested, on the upper two floors of a warehouse, with a kitchen furniture makers on the ground floor. But it was a deceptive building, much higher on the side where it overlooked the River Croal.

There is no sign of the original building today. It stood where the multi-storey car park stands today, and even the river is hidden from view in a culvert.

Inside, a single timber staircase led to the dance hall and bar.

On the fateful night customers were upstairs, drinking and dancing to tape-recorded music and playing the elaborate one-armed bandit which was a feature of the place.

Downstairs, club manager Bill Bohannon smelled a whiff of smoke and investigated.

His search took him to the ground floor where he noticed smoke creeping under the door which led to the workshops.

He kicked in the door and found himself looking into a blazing inferno. The Top Storey Club disaster had begun.

He tried to get back upstairs, but was forced back by the intense heat.

The narrow staircase acted as a chimney of death, funnelling the smoke and flames directly onto the dance floor.

The men and women enjoying a night's drinking and dancing just moments before had nowhere to go -- no way to avoid the choking inferno the little club quickly became, save for the windows opening into the black night.

One survivor, Gillian Grimshaw, later spoke of those moments from her hospital bed. As the heat built up alarmingly, most of the people crowded to the windows on the river side of the building.

They were gasping for air. Some sought protection by crouching beneath the bar, the men trying to shield the women with their bodies.

Gillian was one of those at the window. Somehow, she lost her balance and fell out backwards, down the 80 feet towards the river.

The next thing she remembered was being on the river bank, not knowing that she had been saved by her brother-in-law, Bill Bohannon. He held out his arms and tried to catch her as she fell. Sadly, Mr Bohannon, himself injured, could not save his own wife, Sheila, who was later named among the dead.

Fifteen of the dead were clustered in the bar areas. Three others had jumped from the window into the rain-swollen waters of the River Croal below, and lived. Four others didn't make it.

The body of one young man was washed a mile downstream in the fast-flowing water.

As a graphic account in the BEN stated: "As onlookers -- including policemen on their way home from a dance at the former Palais -- watched horrified and helpless, bodies fell one by one from windows, thumping down on the paved bed of the river."

It took firemen from Horwich, Leigh and Radcliffe almost two and a half hours before they could even recover the bodies from the still-warm club.

Those who died were found huddled in the bar area.

The fact that the club was on the top storey had hampered the rescue severely. Even the turntable ladders did not reach the upper windows.

Hinges

Tragically, there was a loading door which two people had tried to open, not realising that the door's movement was restricted by a false floor and it had to be lifted off its hinges to open.

On the night of the fire, on the other side of a door, a large furniture van had been parked outside the club close to the wall.

Clubgoers could have jumped onto it in an easy escape route. Safety had been only feet away, but they never knew.

Investigators found an empty thinners' tin near the seat of the blaze, but it was never established that the blaze was started deliberately.

One of the few survivors, jazz singer Pedro Gonzales, who had worked at the club, alleged that his ex-bosses there "had a lot of enemies".

An inquest returned an open verdict on all 19 dead.

But the lessons of the Top Storey were swiftly learned. Safeguards were put in place that formed the framework of official controls today.

A spokesman for Bolton police confirmed that, if new evidence on the tragedy ever came to light, it would be considered. However, everything would have to be looked at in the context of the passage of time.