IT is a night Alan Crossan will never forget, and even a year on he can remember almost every minute as the devastation unfolded before him.

The Glasgow pub owner was not in the Clutha on November 29, 2013, as he was recovering at home from a heart attack, but he was on the scene within minutes, staring in disbelief at the sight that confronted him.

Now, almost 12 months later, as he enters the pub, it is a stark reminder of a Friday night that quickly turned to horror when a police helicopter crashed through the roof, killing the three people on board and seven inside the venue.

A bottle of Southern Comfort props up a fallen wall. Along the bar, on tables and across the floor, dust-filled pint glasses, scattered straws and buried bottles of tonic water stand as silent witness to the moment.

The "Rock the Clutha" mural still covers the back of the low stage, while yellowing gig listings, photographs of old Glasgow and a rain-stained Paolo Nutini poster decorate the walls.

It is a chilling scene.

Mr Crossan, standing next to a broken section of the bar, said: "This is where the helicopter came down. It's very unsettling to be here."

The grandfather-of-four was at his home in Crossmyloof when his partner Gill got the call.

He said: "I'd had a heart attack a couple of weeks before, lucky white heather stuff.

"My manager phoned up and spoke to Gill. He said: 'Don't tell Alan but the roof's came in.' I could see the panic in her face. She said: 'How can that happen?'

"Literally 30 seconds later he phones back and says 'a helicopter's come through the roof'. I headed down straight away and police were all around."

When Mr Crossan, 61, reached the Gorbals, at the other side of the Albert Bridge from the Clutha, he stared in disbelief at the site that confronted him.

He said: "I thought: 'How the hell can that happen?'

"It was something out of a film. My immediate thought was: 'Who's injured?'

"I was getting reports back on members of staff who were found."

The popular Clydeside pub was packed with people watching ska group Esperanza perform when the helicopter plunged out of the sky and crashed through the roof.

PC Kirsty Nelis, 36, PC Tony Collins, 43, and pilot David Traill, 51, were killed. Pub-goers Gary Arthur, 48, Samuel McGhee, 56, Colin Gibson, 33, Robert Jenkins, 61, Mark O'Prey, 44, and John McGarrigle, 57, also died at the scene. Joe Cusker, 59, died in hospital 13 days later.

Mr Crossan remembers each moment of the night clearly as the injured were brought out the venue and relatives rushed to the scene to look for their loved ones.

He said: "You had young John McGarrigle outside. Where his dad John stands is right on the spot where the helicopter came through. He knew 100 per cent that's where his dad stands.

"The boy's standing outside, desperate, as anybody would be. I remember it vividly - almost every minute of it."

Mr Crossan needed medication for his heart, so police took him home and then, at around 2am, they brought him back to the Clutha.

He finally returned home at 5am but could not take his eyes off the blanket TV coverage.

The businessman, who also owns the neighbouring Victoria Bar and Millport's George Hotel, took over the Clutha about eight years ago, so knew some of the regulars.

He said: "I knew John McGarrigle but I didn't know the other victims.

"The Clutha wasn't a local pub, it was a destination - so you had a boy like Mark O'Prey, from East Kilbride. You had others from all over. They would all come in at different points. I wasn't there all the time. But when I did go in you knew the faces, the staff and everybody else."

The effects of the disaster were far-reaching and Mr Crossan believes more could have been done to help.

He added: "There were a lot of people affected. The authorities might have done a wee bit more for them. There's maybe lessons to be learned in the future.

"There's people who were killed, people injured and people affected in other ways, and that whole circle should be looked at."