At least 33 people were killed on Thursday morning when the roof of a private school in Peshawar collapsed through the floors below during morning classes. Lady Reading Hospital, where the victims were taken, put the toll at 32 children and a female teacher, with the children aged between six and 14. More than 50 people were injured. The roof of the Al-Khair Education Center in the city's Dir Colony gave way after heavy overnight rain, and police — who arrested the school's owner — say the building was weak, overloaded and built with substandard roof slabs.

What happened at the Al-Khair school?

Emergency services were alerted at 08:48 local time, shortly after lessons had begun, according to the BBC. The roof of an upper-floor classroom collapsed and crashed through the ceilings below, trapping children inside three classrooms — one on each floor of the three-storey building — with around 110 students in them: some 30 pupils on the top floor, 40 on the middle floor and 45 on the ground floor, officials told the BBC. Rescue officials said the upper-floor roof had become unstable after heavy overnight rainfall, Bilal Ahmed of the local rescue services told CNN. The school served about 1,200 students from nursery to fifth grade.

Counts of the dead differed as hospitals reported through the day. Lady Reading Hospital confirmed 33 dead — 32 children and a teacher — to Dawn, and said 53 patients were brought to the hospital in total. The BBC reported a toll of 34 after another child died at the city's Naseerullah Khan Babar Memorial Hospital, and the Associated Press put the number killed at at least 35, with more than 50 injured. A police first information report (FIR), registered later, recorded 30 children and a teacher killed and 52 people injured.

How did the rescue unfold?

Local residents were the first to reach the scene and began pulling children from the rubble with shovels and their bare hands before Rescue 1122 teams and Pakistan Army personnel joined the operation, according to CNN and the BBC. The school stands on a narrow street where only one vehicle can pass at a time, which the BBC reported hampered ambulances and rescue workers trying to reach the site and move the injured. Rescue officials said heavy machinery could not be used freely on the unstable structure. An English teacher from a nearby school told the BBC he personally pulled six children from the debris. Lady Reading Hospital declared an emergency as the injured arrived; rescue efforts stretched into Thursday afternoon and concluded once everyone trapped beneath the rubble had been pulled out, emergency services told CNN.

What have police said and done?

Peshawar's capital city police officer, Mian Saeed, said the three-storey structure was overloaded and had substandard roof slabs that could not bear the weight, and that the building was in a dilapidated condition. "This is a case of gross negligence," he said, according to the BBC, adding that investigators would examine whether building codes had been violated. Police arrested the school's owner — named in reporting as Khan Muhammad — on Thursday. According to the Associated Press, the owner blamed this week's rains for weakening one of the roofs; that explanation has not been independently verified.

Police then registered an FIR at Agha Mir Jani Shah police station under Section 322 of the Pakistan Penal Code, which covers death caused without intent to kill. The News, reporting the FIR, said it names the school's owners, shareholders and construction contractor, alleges that substandard construction materials were used in a building that was dilapidated and unsuitable for use as a school, and states that 52 people were injured.

What has the government ordered?

President Asif Ali Zardari called the collapse a "heart-wrenching tragedy" and demanded a comprehensive investigation; Prime Minister Shehbaz Sharif expressed condolences and directed that the injured receive the best possible care, CNN reported. Khyber Pakhtunkhwa Governor Faisal Karim Kundi ordered a structural safety audit of educational institutions across the province, to identify risks and ensure corrective measures are taken, and announced financial assistance of one million rupees for each bereaved family and 200,000 rupees for each injured person. The provincial government formed a committee to investigate the cause, and the province's education secretary directed the Private Schools Regulatory Authority to submit an incident report by Friday.

Building collapses are a recurring disaster in Pakistan: CNN notes that construction standards in the country are often poorly enforced and many structures are built with substandard materials. What the overnight rain found in Dir Colony on Thursday morning was a school roof that the city's own police chief says could not carry the children beneath it.

Casualty figures are attributed to the hospitals, police and news agencies that reported them and differed as counts were updated through Thursday; the FIR's figures are the police record, not a court's findings, and no suspect has been convicted.