The series focused on the Germans’ brutal attack on the Spanish city of Guernica during the Spanish Civil War in April 1937 that first introduced the concept of “Carpet Bombing”. While cities in Spain had been bombed by the Germans earlier in the war, Guernica was unique because it was both a military experiment conducted against a defenseless civilian population, and it left the city totally destroyed. Fewer than one percent of the buildings were left unscathed and while the official death toll was 1,654, many more were left forever buried under the ruins.