The AC plant where the fire started on Tuesday. Picture by Sanat Kr Sinha

A fire broke out in an external air-conditioning plant of a four-storey building on the National Library compound on Tuesday but was contained by two fire engines.

None of the 23.5 lakh books and other documents stocked in the sprawling 40,000sqm building, Bhasha Bhavan, was damaged, National Library officials said.

Sparks and thick smoke were spotted at the AC plant around 4pm. Two fire engines arrived within 10 minutes and sprayed foam on the source of the fire to put it out in about 10 minutes.

Fire department officials said the fire was caused by an electrical short circuit in one of the panels of the AC plant.

National Library officials said there were about 250 people inside Bhasha Bhavan, including about 100 people in the reading room, when the fire was detected in the AC plant, 60m away from the building, across two driveways and a parking lot.

A similar fire in the basement of AMRI Hospitals, Dhakuria, had left 91 people dead in 2011.

According to fire officials, National Library, too, did not have smoke or heat detectors that could trip the AC motor and cut off air supply from the plant to the building in case of a fire.

“Had it been a bigger fire, there would have been a chance of carbon monoxide spreading to Bhasha Bhavan through the AC ducts,” said a senior fire official.

Even before the firemen arrived, employees of CPWD, who are in charge of maintenance of electrical and civil facilities and the gardens at the National Library, switched off power to Bhasha Bhavan. Readers left the library at this point.

“Thick smoke had filled the area when we reached the AC plant around 4pm. There were oil barrels strewn about. The matter could easily have gone out of control. The CPWD has an annual contract of Rs 4 crore but their maintenance is shoddy,” said Saibal Chakraborty of the National Library Staff Association.