In 1961, the British official historians, Charles Webster and Noble Frankland wrote that Bomber Command sent with on Berlin. The attacks cost their crews killed or captured and damaged, a rate of loss of 5.8 per cent, exceeding the 5 per cent threshold that was considered by the RAF to be the maximum sustainable operational loss rate. The Battle of Berlin diverted German military resources from the land war and had an economic effect in physical damage, worker fatalities and injuries, relocation and fortification of industrial buildings and other infrastructure but by 1 April 1944, the campaign had failed to force a German capitulation,