The roof of Hotel City Light and Bakery, located on Rashtrapati Road, gave way at around 6.30 AM resulting in the building collapse that left 13 people dead and 18 others injured, officials said.
"The injured were shifted to Gandhi Hospital, where five among them were discharged while doctors performed surgeries on four others," Secunderabad District Revenue Development Officer Ravindra Babu told PTI.
The deceased included hotel staff and customers.
"It is based on the prima facie report, as the building itself was between 75 to 80 year-old. Further probe is on in this regard," he said.
The officer said that construction for setting up 7-8 kilns to prepare 'Haleem'--a delicacy made during Ramzan season--was going on on the building terrace, where around 40 workers of the hotel are staying.
"We are told that furnaces for preparing 'Haleem' are being constructed in the upper floor. A water tank is also said to be there and there were seepage from the tank.
"The combination of factors like the seepage, weight of the furnace or heat, might have made the structure weak. The building was not constructed on pillars. If any wall weakens then entire slab can be pulled to that side," he said.
Meanwhile, Mahankali police have booked a case of negligence against hotel owners.