A fire broke out in a high-rise building in Istanbul on Tuesday but officials said hundreds of people were quickly evacuated and no one was hurt. Black smoke rose from the 42-story Polat Towers that is partly residential and partly occupied by shops and businesses until firefighters brought it under control. Smoke covered the sky. The cause of the fire was under investigation but Istanbul's Gov. Huseyin Avni Mutlu said an initial inspection indicated that it was caused by a technical fault at a section containing air conditioners. State-run TRT television said the fire, fanned by winds, burned through the building's external wall insulation. Mustafa Sarigul, the mayor for the district of Sisli, where the building is located, said the inside of the building was not affected. "The building's fire-extinguishing system automatically activated," Sarigul said. "Otherwise we could have faced a huge disaster."