The driver was among the 10 people injured. Seven of the injured were taken to hospital by the ambulance service, two walked into hospital and one was treated at the scene. Four have since been discharged.
Six people currently remain in hospital being treated for their injuries. Two have been moved to the Intensive Therapy Unit for further monitoring.
As tributes to the dead poured in The Queen sent a message of condolence to the Lord Provost of Glasgow, in which she said her "thoughts and prayers" and those of the Duke of Edinburgh were with those who lost loved ones and those injured in the bin lorry disaster.
John Sweeney, a relative of Mr and Mrs Sweeney in Toronto, Canada, posted on Facebook that he was "feeling heartbroken".
Jack Sweeney, 68, was killed alongside his wife Lorraine and granddaughter Erin. Photo / Facebook
He wrote: "No words can describe the pain. R.I.P. Jack, Lorraine and Erin. Thoughts and prayers go out to the other families that lost loved ones as well."
Jack Sweeney, from Dumbarton, was a former president of Bramalea Celtic supporters' club in Ontario, Canada.
A spokesman for the club said: "It is with great shock and sadness we share with you our friend and past President Jack Sweeney, his wife Lorraine and granddaughter Erin were victims of todays tragedy in Glasgow. Our thoughts and prayers go to the Family and friends of the Sweeney family."
A neighbour of the Sweeney family in Dumbarton said: "We're absolutely devastated."
Mourners leave flowers at the scene of the crash. Photo / Getty Images
Alastair McCulloch, a family friend, described how Erin's mother Jacqueline McQuade, 43, saw her daughter and her own parents killed in the accident.
He wrote on Twitter: "Really sad. Partner of a friend of mine lost 3 of her family in the Glasgow RTC. She witnessed her parents and her daughter killed. #Tragic."
Photographs of Erin show a striking girl, clearly popular with a large circle of friends across the west of Scotland, and those who knew her described her as "bright and engaging".
The teenager had recently begun an English literature degree at the University of Glasgow.
Three bunches of flowers left were left at the gates of St Philomena's Primary School, in Glasgow, where Miss Tait worked as a teacher.
Catherine Gallagher, the school's head, described Miss Tait as "excellent and dedicated" to her pupils, adding: "The entire school community is deeply saddened by this tragic news.
"Our thoughts and prayers are with her family and friends at this time.
Erin was described as bright and engaging by her friends.
"We will be supporting colleagues in every way possible. Stephenie made a wonderful contribution to the life of St Philomena's. She will be sadly missed by both pupils and staff."
Among the floral tributes was one which said: "So sad, thinking of you and your family in our prayers. RIP Miss Tait."
A distraught mother and daughter who left flowers at the gates of St Philomena's Primary School said Miss Tait was a popular teacher and a "lovely person".
Selina White, a former pupil, wrote on Twitter: "Absolutely gutted to hear one of my primary teachers was involved in that accident in George Square yesterday. RIP Stephanie Tait."
Another Twitter user wrote: "RIP Miss Tait was such a great teacher when I had her in primary. Rest in peace. Condolences to her family and friends."
The disaster happened when the lorry hurtled along George Square, which was filled with children enjoying an ice rink and fairground at a Christmas market, before crashing into the Millennium Hotel.
The first casualty was a pedestrian who was hit near the Gallery of Modern Art, while most of those killed or injured were in the bustling square. Eyewitnesses said they saw people knocked over "like pinballs", including a baby in a pram.
Police said the area was full of families at the time of the incident. Bystanders said the driver appeared to have had a fit or a heart attack at the wheel.
Police Scotland said in a statement: "Four people have been discharged from hospital and six are currently receiving treatment for their injuries, including the driver of the lorry.
"Four patients remain in Glasgow Royal Infirmary. One patient is expected to be discharged later today, one patient is in a critical condition, one patient is serious but stable and one patient is stable.
"A further patient who is being treated at the Western Infirmary is in a stable condition. The sixth patient, who is being treated at the Southern General Hospital, is expected to be discharged later today. "
Shoppers described the terror as the lorry careered into the crowds enjoying the annual winter carnival with their families.
Melanie Greig, who had been out shopping, said: "The lorry just lost control, it went along the pavement knocking people down like pinballs. There was a baby in a buggy, there were two little kids.
"People were trying to run out the way, but when something like that comes up behind them how can they? There was noise and bangs and screams."
Findlay Mair, 23, said: "The screaming just kept going on. Suddenly it was just chaos. Some people were running towards the scene, others were just standing stock still, in shock.
"The people who were hit had no time to take evasive action. They had no chance.
"I saw one girl who had been hit, lying on the ground. She got up, and blood was pouring from her mouth, then she went down again."
He added: "A woman got out of her car and just stared at what was unfolding and then started sobbing. She was yelling 'Oh God, oh God'.
"There was Christmas shopping littered everywhere, among the bodies and bits of the vehicle. Time seemed to stand still. It was a terrible, terrible scene.
Scotland's First Minister Nicola Sturgeon said the city was waking up with a "broken heart".
She told BBC Radio Scotland: "As the city wakes up this morning, the sheer sense of horror and grief that happened yesterday will be very, very raw for people."
