The fire was detected at 3.50 AM in the 25-year-old Surya Sen Market complex housing a godown-cum-office complex when the victims, mostly labourers working in the market, were sleeping, vice-chairman of the market Sushanta Ghose said.
The staircase of the market complex was blocked with goods making it difficult for the people to escape the inferno, Ghose said.
According to fire officials, plastics, paper and cloth were stored in the godowns. The ground floor and the first floor of the complex, which sustained the maximum damaged, housed 200 shops.
Ghose said there was only one proper entry and exit route of the complex. Though there was one emergency exit, it was not used for the last 15 years, he said.
According to locals, the complex was stuffed with inflammable articles like plastic, cloth and gas cylinders.
The cause of the fire is not yet known.
West Bengal Chief Minister Mamata Banerjee, who visited the market, directed police, fire brigade and municipal corporation to submit a report on the fire within three days and announced a compensation of Rs two lakh to the kin of those who died.
"A compensation of Rs two lakh will be paid to the kin of those who died in the fire and Rs 50,000 to those injured," she said.
The chief minister urged people sleeping in the market in the night to be more careful and take precautionary measures like not lighting a fire near inflammable materials.
"They should be more careful. Mischief-makers also can cause damage.Everything will be investigated to find out the cause of the fire," she said before leaving for the Medical College morgue where bodies of the victims were taken.
Fire Services Minister Javed Khan said six persons were brought out from the burning godown in an unconscious state by firemen who were trying to find if others were trapped inside.
The injured were rushed to state-run NRS and Medical College hospitals.
Firemen and police personnel cordoned off the area to facilitate fire fighting operations, Khan said.
Joint Commissioner of Police (Headquarters) said, "19 people have been killed and several others are injured."
He said 26 fire-tenders fought the blaze for over three hours to bring the situation under control.