Warning of the raid was given fifteen minutes in advance by leaflet and Seoul radio to enable the civilian population to leave, but pilots reported that they saw no sign of movement. More than forty military targets in the city, including troop headquarters, railway yards, power stations, factories and air strips were attacked … ‘The town was blowing up all over’, said one of the returning pilots. ‘The smoke was the blackest I have ever seen. It was so black that visibility was zero.’ 1