Explosions rocked the Nandaram Market building in Burrabazar on Sunday evening where firefighting has failed to douse a raging blaze even after 48 hours.
The explosions, caused either by a gas cylinder or 300 litres of diesel stored in the 12th floor generator room, could lead to the crumbling of the 13-storey structure, Police Commissioner Gautam Mohan Chakraborty said. The building has already tilted a little to the left and after the explosions, cracks have appeared.
As the eruptions were heard, people scurried for cover and fire fighers retreated in panic.
The blaze that began on the intervening night of Friday and Saturday has already gutted over 3,000 shops in the congested market. Parts of the adjacent Kashiram block have also started caving in.
One person died of heart attack after his shop was destroyed.
As the blaze showed little sign of subsiding, jawans and fire brigade officials in gas masks entered the building to fight the fire from the source, but a few fell ill and were rushed to hospital.