Rescue workers survey the wreckage of a police helicopter which crashed onto the roof of the Clutha Vaults pub in Glasgow, Scotland November 30, 2013. [Photo/Agencies]

The younger McGarrigle, who described his father as a regular at the bar who sat in the same seat every night, had arrived on the scene shortly after the crash and stayed all night.

"His friend told me she went to the toilet, heard the noise and went back into the bar," he said. "He was gone. There was nothing left where he'd been sitting."

The crash Friday at around 10:30 p.m. sent dozens of patrons fleeing through a cloud of dust. Witnesses spoke of people streaming out of the building covered in blood, with gashes and other injuries.

Local resident Paul Dundas, 26, told how he heard a loud bang and looked out of his window to see a plume of dust rising above the pub.

"At first I thought it was a firework," he said, describing the "horrible scene" he discovered upon going down to the street level.

"People were covered in blood and dust. Other people were dragging them away from the bar and trying to get them out," he said. "Everyone was in shock, but people were helping and asking strangers if they were OK. I saw a couple help each other clean up their faces.

The twin-engine Eurocopter is widely used by police and ambulance services.

In 2007, a Eurocopter EC135 T2 crashed in southern England. The pilot and his wife were unhurt, but the aircraft was badly damaged. Britain's Air Accidents Investigation Branch said there had been a failure of the autotrim system which maintains the aircraft's position. The agency recommended changes to correct the problem.

Esperanza, the band which was playing in The Clutha when the crash occurred, joined in the heaps of praise showered on rescue officials.

"Waking up and realizing that it is all definitely horribly real," the band wrote on its official Facebook page. "Despite the situation everyone was so helpful and caring of each other. The police, ambulances, firefighters all did a stellar job and continue to do so today."

Glasgow, a city of about 600,000 people, has transformed its traditional image of being a rough and tumble city to one with a vibrant music and arts scene. It was also among the cities that hosted Olympic soccer matches in 2012 and will hold the Commonwealth Games in 2014.