It was a tragedy beyond comprehension. Soldiers who had survived the trenches, civilians who had weathered shortages and bombardment, now faced a new enemy: influenza. The virus tore through societies already weakened by war in 1918. According to one British nurse who recorded an interview with the Imperial War Museum, 'the mortuaries were so full we had the patients lying one on top of the other'. Dan Snow hears the accounts of those who survived it, from those in the front line and Prisoner of War camps, to those who were schoolchildren at the time in Britain, and were forced to look after their families and neighbours.