Tuesday night, fires separately broke out at a garment factory in Karachi and a shoe factory in Lahore.
The death toll from a pair of devastating factory fires that broke out in Pakistan's two biggest cities rose on Wednesday to 314 people, many of whom perished because they were unable to escape buildings that lacked emergency exits and basic safety equipment such as alarms and sprinklers.
The horrific toll highlights the atrocious state of industrial safety in Pakistan, where many factories are set up illegally in the country's densely populated cities, and owners often pay officials bribes to ignore safety violations.
The more deadly of the two blazes, which both erupted on Tuesday night, was at a garment factory in the southern city of Karachi, the country's economic heart.
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The death toll there rose to 289 people Wednesday, as firefighters battled the flames for hours, said senior government official Roshan Ali Sheikh. It was one of the worst industrial accidents in Pakistan's 65-year history, and Sheikh said the death toll could rise because rescue workers were still pulling bodies out from the site in Karachi.
Most of the deaths were caused by suffocation as people caught in the basement were unable to escape when it filled with smoke, said the top firefighter in Karachi, Ehtisham-ud-Din. There were no fire exits, and at least one of the main doors leading out was locked, he said. It's unclear what caused the fire.