Between 100,000 and 200,000 refugees fleeing westward from advancing Soviet forces were in the city at the time of the bombing. Exact figures are unknown, but reliable estimates were calculated based on train arrivals, foot traffic, and the extent to which emergency accommodation had to be organised. The city authorities did not distinguish between residents and refugees when establishing casualty numbers and "took great pains to count all the dead, identified and unidentified". This was largely achievable because most of the dead succumbed to suffocation; in only four places were recovered remains so badly burned that it was impossible to ascertain the number of victims. The uncertainty this introduced is thought to amount to no more than 100 people. 35,000 people were registered with the authorities as missing after the raids, around 10,000 of whom were later found alive.