At least 31 people have been killed in what the Turkish prime minister has called the worst flood Istanbul has ever seen.The worst damage was done in low-lying areas on the western, European bank of the city. Some of the victims were swept away by strong currents. Others drowned in cars, minibuses and lorries, having been taken completely by surprise by the rising floodwater. Turkey’s Interior Minister, Besir Atalay, said that 24 of the confirmed casualties were in Istanbul, while seven had probably perished in Tekirdag, 135 kilometers to the west. There were also reports of massive disruption in neighbouring Bulgaria. The floods follow the heaviest rainfall in the area for 80 years, according to the Turkish meteorology centre. The rain started late on Monday and more is forecast in the next few days. Insurers estimate the cost of the damage already done could reach 100 million euros but the more pressing worry for residents is a rising death toll.