At least one person was killed and four others were left under rubble after an eight-storey residential building collapsed in Istanbul, Turkish private broadcaster NTV said on Wednesday, Reuters reported. It was not immediately clear why the building, in the Kartal district, had collapsed. Police, ambulances and firefighters were sent to the site, NTV said. Emergency teams were trying to reach the four individuals left under the rubble, NTV said. According to AP, Zeki Dag, the local district administrator, told CNN-Turk television that more than a dozen families were living in the building.