Updated - Dec. 3, 2:35 a.m. ET:
Nine people died in the crash, reports the BBC.
Three of them were in the helicopter, Sir Stephen House of the Scottish police told a press conference.
All nine victims have now been named — David Traill, the civilian pilot, 51; Kirsty Nelis, the police constable, 36; Robert Jenkins, 61; Mark O'Prey, 44; Colin Gibson, 33; John McGarrigle, 57; Tony Collins, 43; Samuel McGhee, 56; from Glasgow; and Gary Arthur, 48, from Paisley.
The helicopter crashed through the roof of the Clutha Vaults pub, Stockwell Street, Glasgow. The tail of the chopper is visible in this photo.
Labour MP Jim Murphy was at the scene and reported multiple injuries.
It's a well established Glasgow pub. It's a horrible, horrible scene, but well done to the folk who were here. Everyone formed a chain of people from inside the pub to outside, and the fire brigade and everyone were here very quickly.
U.K. Prime Minister David Cameron offered his condolences on Twitter:
He would later thank the emergency services.
He also paid tribute to the bravery of the "ordinary Glaswegians who rushed to help."
As did the First Minister.
Gordon Smart, editor of The Sun's Scottish edition, saw the crash. He told Sky News:
There was no fire ball and I did not hear an explosion. It fell like a stone. The engine seemed to be spluttering.
Firefighters worked through the night to free those trapped in the rubble.
This is an unimaginable horror and my deep condolences go out to those who have died or been injured [...] My thoughts are with them and also with the people of Glasgow. They've shown great bravery and great calm. I've been in contact with Jim Murphy - he showed great presence of mind to help out those who have been injured.
Our hearts go out to everyone who has been bereaved. They should know the thoughts and prayers of everyone across the city and in Scotland are with them.