Next month Pope Benedict XVI will mark the anniversary of a brutal massacre that took the lives of 335 Italians during World War II.On March 24, 1944, Nazi soldiers slaughtered the hundreds of individuals to exact revenge for a surprise bomb attack in the heart of Rome that killed 33 of their colleagues.When he heard of the attack, Adolf Hitler ordered that 10 Romans be rounded up for each Nazi casualty.The Nazi commander in Rome took all those on death row in a military prison, but they did not equal the number Hitler had ordered. He added 75 Jews, political prisoners, individuals in jail for petty crimes and civilians present at the attack to the group to reach the figure. The final count proved to be higher than 330.The 335 victims were led into the caves of a quarry by soldiers who were driven by commanding officers to kill each of them, one-by-one, with a shot to the back of the head.