Witnesses said a client smashed the window and jumped from the second storey before he and some passersby wheeled an industrial bin over to the window to allow four trapped workers to escape.
The fire broke out just after 6pm at a massage business on the corner of Rundle Street and Vaughan Place in the middle of the city.
9News obtained exclusive vision of a stairwell on fire, as well as a woman running down that stairwell trying to get away.
It is understood the building has multiple businesses inside of it.
Police believed the fire was deliberately lit, although the business’ owner told 9News she thought it was an accident.
Most of the building was saved it’s feared the damage bill could top $200,000.
Four people were treated for minor injuries including smoke inhalation.
