Exploding cylinders which were “effectively like a bomb” meant firefighters had to tackle a huge fire at a workshop in Speedwell from outside the building.
Emergency services were called to the Strachan and Henshaw Building, based on Foundry Lane, just after 6pm on Friday night (May 3).
Almost 24 hours on from the initial call, firefighters are still at the scene and in the process of dampening down.
At the height of the blaze, which spread from the workshop to a neighbouring office block, there were more than 76 firefighters and officers at the scene.
According to Avon Fire and Rescue Service, 40 homes were evacuated as a result of the incident.
Some families went to Croft End church while others have been welcomed into strangers' homes.
Group manager Steve Quinton has now revealed more details about the blaze and how and why decisions were made on the night.
He said: “We received a call at 6.20pm last night to a severe fire in a workshop on the ground floor.
“The officers in charge quickly called in additional resources and made a decision not to commit people at that stage into what was a very dangerous environment, which has turned out to be the correct decision.
“The initial officer started to commit crews and then these cylinders started to gas off and explode, effectively like a bomb.
“We put a 200 metre cordon in place due to the cylinders involved in the fire because they presented a serious risk to our firefighters and members of the public.
“So a decision was made to evacuate 40 properties for their safety I would like to thank members of the public for their assistance.
Mr Quinton confirmed not a single firefighter or member of the public had been injured as a result of the incident.
Crews were still on scene on Saturday afternoon dealing with some hotspots within the building and turntable ladders were being used as water tower monitors to extinguish the fires that kept flaring up inside.
At around 2pm on Saturday the majority of people evacuated were able to return home - there were just three properties unable to do so because of the cordon.
Mr Quinton also praised his colleagues at Avon and Somerset Constabulary and the Bristol City Council emergency planning team.
He added: “As organisations we plan for these events and obviously the plan worked last night and we would like to thank our colleagues for their assistance.”
