Kolkata Municipal Corporation (KMC) on Thursday ordered demolition of the sixth and seventh floor of Stephen Court, the heritage building which caught fire on Tuesday claiming 24 lives so far with at least 25 others still missing.

Originally a five-storied building, two more storeys, six and seven, were added to Stephen Court in 1984. This, according to fire department officials, had endangered the structure.

In fact, Stephen Court, a landmark building of Kolkata, did not fall under the tall building category as long as the two extra storeys were not added. But after addition of the sixth and seventh floors, it crossed a height of 14.5 meters, which demanded a ?tall building clearance? from fire department authorities. But that was never taken.

? We don?t have Stephen Court in our list of tall buildings,? Achintya Mukherjee, divisional fire officer, said. A tall building has to have a different structure with alignment of staircases, room entrances and corridors. “Stephen Court didn?t have anything mandatory for tall buildings and so its structural safety was endangered,” Mukherjee said. On Tuesday, when the fire broke out, the real fire-fighting began 85 minutes late, once the hydraulic lifts arrived, because the water from the fire brigade jets couldn’t reach the high structure.

For converting a normal building into a tall structure, one needs to take a KMC permit, which can be obtained only after a superintending engineer issues a structural safety certificate after going through the plan. The plan has to comply with certain fire department obligations before getting a structural safety certificate. But in case of Stephen Court, this rule was violated, a fire department official said.

KMC?s director general building-II Debashish Kar said KMC authorities identified the new construction in the building as irregular, which may have been legalised later after paying a penalty. Kolkata Municipal Act of 1951 has such a provision under rule 77 and such a provision must have been applied for transforming Stephen Court from a five-storey building to a seven- storey one, Kar said.

Arunabha Ghosh, an eminent lawyer and a former MLA, said there is a huge gap between fire department rules and KMC rules on buildings and there are legal provisions to escape such safety norms.

In fact, the fire department has been changing and updating its rules which the KMC has not been taking into account, Ghosh alleged. ? I discovered it when I was pleading the case of the13 storey building fire at Nandaram Market in Barabazar, which happened in 2008,? he added. Besides tenants and lessee also break safety norms by blocking doors, windows, erecting false ceilings and arranging rooms in their own way, Ghosh said. That’s what happened at Stephen Court too. All the staircases were blocked, and the door to the terrace locked, thus trapping many more.

Kar said there were no documentary evidence with the KMC to find the additional construction?s original status since it was made 30 years ago. KMC doesn?t maintain such old records. ?If owners of Stephen Court has kept the papers, then only we can know under which legal provision were the additional two floors constructed,” Kar said.

The fire brigade has planned to crush the debris on the spot before it starts clearing the mess. It is not yet decided when it can start the salvage work.

Meanwhile, business of Park Street limped back to normal, but the eateries at Stephen Court, including Flury’s and Peter Cat, remained shut. RPG’s popular store MusicWorld, one of the group’s most commercially successful retail stores, too remained closed.