The ground beneath a building which collapsed crushing three workmen was deemed unstable months ago, the Evening Times can reveal.

The men, who are understood to work for contractor Soil Engineering, were at the Botanic Gardens garage on Vinicombe Street when the accident happened yesterday.

Around 1.55pm, three men were leaving an outbuilding behind the grade A-listed Edwardian garage when the front wall collapsed entirely on top of them.

Their colleagues looked on in horror as the men were crushed by mounds of falling bricks, before emergency services were called.

Two of the men, thought to have suffered injuries including broken limbs and cracked ribs, were taken to the Queen Elizabeth University Hospital by paramedics.

The garage building, owned by motoring tycoon Arnold Clark, is set to be transformed into a shop and 24-hour gym after lying derelict for years.

During an investigation earlier this year mine workings were found below the garage which could cause damage in the surrounding soil and ground if untreated.

Arnold Clark said previously that "any such damage would affect ground stability and could undermine the structure of the existing building."

The firm also said they would need to inject grout to stabilise the mine shafts, to make sure "ground instability will no longer be an issue to the building and its neighbouring properties."

Although Arnold Clark could not confirm the exact work the contractors were carrying out, Soil Engineering's website states the company "is one of the UK’s leading geotechnical contractors with a proven capability in all elements of ground investigation and stabilisation."

One eyewitness said: "It could have happened to anyone. They were just going to get their dinner when the whole thing fell."

The witness added that work was not being carried out on the building which collapsed, but equipment had been stored in there.

Around a dozen police officers were at the scene yesterday afternoon taking statements from workers in orange Soil Engineering jackets.

They cordoned off the site and vehicles were blocked from going near the building in case vibrations disturbed the already damaged structure.

Glasgow City Council's building control and the Health and Safety Executive (HSE) are now investigating the incident.

An HSE spokeswoman said: “HSE is aware and understands the responsibility for the ongoing structural stability lies with GCC building control

“When appropriate HSE inspectors will be on site to determine the cause of the incident. “

A Glasgow city council spokesman said: “Our building control team is working with the contractor to ensure measures are taken to make the site safe.”

Arnold Clark said: "We are aware of an incident that has occurred at the Vinicombe Street site and we are working with the emergency services at this time.

"We will be conducting a full investigation in due course and at the moment our priority is to assist the team of contractors that have been affected."

Soil Engineering refused to comment when contacted by the Evening Times.