A fire suspected to have started from a mall food court spread to a bookstore overhead, the smoke forcing the evacuation of shoppers, employees and hundreds of people who worked in the office complex at the 21-storey Acropolis in Calcutta on Friday.

This was within 72 hours of the city witnessing an inferno in Camac Street.

People hurried down staircases partially blocked with waste and discarded materials from the renovation of shops and offices. Some stumbled as their legs hit the sacks stacked on the stairs. Though the fire alarm rang, most people mistook it for a routine drill.

There were no serious injuries, but the Crossword bookstore was gutted and several other stores were damaged too.

According to eyewitness accounts, as the fire raged, many inside the mall panicked and were seen running and screaming while security personnel kept asking people to leave.

The mall was relatively empty when the fire broke out around noon, which helped the evacuation efforts. Many wondered what would have happened had the fire broken out on a weekend evening when the mall bustled with visitors.

A video captured by a mall employee showed thick black smoke rising from the Crossword zone and engulfing the Chilli’s restaurant. Although the fire was restricted to this corner, the smoke spread across the mall.

Fifteen fire tenders were pressed into action. Firemen smashed the glass facades of portions of the mall and some of the windows to let out the smoke trapped inside.

A preliminary inspection by fire brigade officers suggests that an electrical renovation on the food court ceiling, just under Crossword, may have caused sparks that led to the fire. “The exact cause will be ascertained only after the forensic report comes,” an officer said.

On Tuesday, a fire broke out in a Camac Street building that houses more than one food-and-drink joint. That fire, too, is suspected to have been caused during renovation. A forensic report is awaited.

On Friday, a smoke extractor machine was put to use, which inhaled fumes and exhaled them outside. On the eastern side, a hydraulic ladder stood on the ground of the adjoining Gitanjali stadium. It broke open windows and sprayed water inside.

By the time the fire had been brought under control, the mall’s facade had gaping holes with irregular-shaped remnants of glass hanging from some. The walkway outside the mall was strewn with shards.

Krishna Jha, senior operations manager at Acropolis, said: “The occupants were evacuated safely. No casualties occurred. The mall is equipped with a robust firefighting and prevention system. We regularly have fire drills and the facility management staff are trained professionals to handle the fire system. The situation is now under control.”

Mainak Chowdhury, who works at the store of a clothing retail company on the second floor, said he had ignored the first alarm. “Alarms often ring during drills. Most of us ignored the first alarm. It was the chaos and screaming of people that alerted us about the fire around noon,” Chowdhury said.

“I pulled the shutter down, locked the store, and left. By then, smoke had reached the ground floor.”

The children’s playpen on the fourth floor had three kids at the time. Munna Lal Agarwal, who owns Simbaa Playzone, thanked his stars that it was early Friday afternoon. On Sundays, the arena has about 50 children and their parents at any point of time.

“We called the parents and helped them go down. Then all the staff and I went downstairs leaving things as they were,” said Agarwal.

Besides the mall, the building has several offices, including a radio station. The portion with the restaurants, shops and multiplex is five-storey tall while the other part with offices is 21 storeys. The rooftop has a popular nightspot.

Fire minister Sujit Bose and civil defence and disaster management minister Javed Khan were at the site during the firefight.

Bose said: “I have asked officials to conduct an inquiry. If anyone is found guilty, appropriate action will be taken. We will inquire into all aspects.”

There was no clarity till late in the evening whether the mall would reopen on Saturday.