Cause of the collapse was not immediately known According to local officials, more than a dozen families living in the building ISTANBUL: 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. It was not immediately clear why the building, in the Kartal district on the Asian side of the city, had collapsed but NTV said prosecutors had launched an investigation into the incident. Istanbul Governor Ali Yerlikaya told reporters at the site that 43 people were registered in 14 apartments at the address, but added that the top three floors of the building had been built illegally. Yerlikaya also said there was a textile workshop on the ground floor of the building that was operating without a license. He declined to comment on the number of casualties. The chairman for Turkey"s Disaster and Emergency Management Authority (AFAD) said search and rescue operations were underway, adding that additional personnel would be requested from neighbouring provinces if necessary. President Tayyip Erdogan sent the interior and environment ministers to the site, state-owned Anadolu agency reported. Television footage showed emergency teams pulling a woman out of the rubble as dozens of bystanders watched near the debris. Aerial views of the area showed roads leading to the building blocked by vehicles and crowds.