The block of flats collapsed moments after a loud bang tore through the building in the Hartcliffe area of the city last night.
One man reportedly fled engulfed in flames during the terrifying scenes as horrified neighbours had to douse him in water.
A witness saw a woman jump from an upper floor window onto a trampoline in a desperate bid to escape, Bristol Live reports.
And another woman had to rush inside to rescue her four-year-old daughter moments before the building collapsed.
The explosion was reportedly so big it shook houses minutes away as emergency services locked the area down.
Locals reported hearing a “humongous bang” before witnessing a fire ripping through the building.
Dramatic pictures later showed the entire frontage of the building had been ripped off by the explosion.
Avon Fire and Rescue Service said three people were treated for injuries in the incident shortly before 8pm.
Steve Imrie, area manager with Avon Fire and Rescue, told Bristol Live: “We committed two crew in breathing apparatus to contain and inspect the fire, while other firefighters began to administer first aid to a number of persons at the scene.
“All casualties were conscious and breathing. Certainly the initial person who was treated has suffered minor burns.”
The cause of the explosion, which many believe to be a gas boiler, has not yet been confirmed. It is not believed to be suspicious.