Rescue workers search for survivors at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, February 6, 2019. At least two people were killed and six wounded after an eight-storey residential building collapsed in Istanbul on Wednesday, the governor's office said. REUTERS/Murad Sezer

Rescue workers search for survivors at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, February 6, 2019. It was not immediately clear why the building, in the Kartal district on the Asian side of the city, had collapsed. REUTERS/Murad Sezer

Rescue workers search for survivors at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, February 6, 2019. Istanbul Governor Ali Yerlikaya told reporters at the site that 43 people were registered in 14 apartments at the address, but that the top three floors of the building had been built illegally. REUTERS/Murad Sezer

Rescuers are seen at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, early February 7, 2019. The chairman for Turkey's Disaster and Emergency Management Authority (AFAD) said search and rescue operations were underway. President Tayyip Erdogan sent the interior and environment ministers to the site, state-owned Anadolu agency reported. REUTERS/Murad Sezer

Rescue workers help a survivor at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, February 6, 2019. Emergency teams pulled at least three people out alive as crowds surrounded the site. Roads leading to the building were blocked by vehicles and crowds. REUTERS/Murad Sezer

A general view of a rescue operation at the site of a collapsed residential building in the Kartal district, Istanbul, Turkey, February 6, 2019. At least two people were killed and six wounded after an eight-storey residential building collapsed in Istanbul on Wednesday, the governor's office said. REUTERS/Umit Bektas