The top four floors caved in on Thursday morning owing to sustained intense heat while thick dark smoke continued to bellow out of the building.
Declaring the area unsafe, the police have cordoned off the busy T.Nagar locality which in turn has affected the business of other organisations for a second day.
Over 150 fire service personnel have been deployed to douse the fire.
Narrow roads and the absence of easy approach hindered the fire service personnel’s efforts to put out the flames early.
The fire broke out early Wednesday early morning.
The cause of the fire is said to be an electric short circuit.
Officials said the showroom had stocked plastic items and clothes. The building had false ceilings which are easily flammable.
The stock-in-trade in the textile showroom is estimated to be worth several crore.