During the period of the holocaust and Nazi persecution, an estimated of six million Jews were murdered due to the unrevealed hatred that was put among them. (USHMM) Countless innocent Jews were taken away from their houses to be worked as slaves and eventually die in unimaginable ways. Millions of Jews faced inhuman treatment once they’ve become prisoners and are sent to concentration camps. Some were lucky, lucky enough that they received a job in the camps and live one day closer to liberation. Most others were not so lucky, they faced cruel treatment and lethal killing methods. Killing Centers, also known as “Extermination Camps” or “Death Camps” were widely used by Nazis to conduct a mass murder of primarily Jews. Killing Centers murdered an estimate of 2,700,000 Jews due to asphyxiation with mass amounts of poison gas such as Zyklon B. One of the intolerable ways Jews were exterminated was the use of Zyklon B. One of the SS doctor described, “…shouting and screaming of the victims could be heard through the opening and it was clear that they fought for their lives. If the gas chamber had been crowded, which they typically were, the corpses were found half-squatting, their skin discolored pink with red and green spots, with some found foaming at their mouths, or bleeding from their ears.” (USHMM) When Zyklon B is exposed to air, it’s converted to a lethal gas. The active ingredient in Zyklon B is hydrogen cyanide (HCN), which once absorbed, it blocks your cells ability to absorb oxygen, leading to suffocation. Death Camps, a place where captured Jews were sent to daily, were suffocated by the usage of Zyklon B under Nazi control. Currently, most operations are meant for mass killings, and the SS needed a method that was capable of killing small amounts of people. Acting as Nazi’s military commander, Heinrich Himmler, and his supporters thought of Gas Vans. Instead of sending victims on a long train ride, the Nazis decided that they wanted to kill them instantly. This method is when victims, enclosed in a small sealed mobile gas chamber. Exhaust fumes were led by a pipe and were transmitted into the mobile gas chamber as the engine was running. Before reaching their destination, usually a nearby forest, where all the corpses gathered and the Nazis dumped all the Gas Van victims into a pile and burnt them, all of the victims died from carbon monoxide poisoning and suffocation. Zofia Szalek, a German residing in a Polish town of Chelmno, witnessed,  “We could hear the screams, but we couldn’t see the people. They were loaded in and murdered there. It was hell. That’s why we called these vans ‘Hell Vans.'” (Laurence Rees) The victims screamed for their lives as they ran out of oxygen, but bystanders can do nothing in their favor since they couldn’t see the victims. She also described Gas Vans as Hell Vans, meaning that the few minutes of yelling and crying for help, yet nobody coming to assist you, indeed, was hell. This method was used only for a short period of time, due to two disadvantages for the Third Reich. The first disadvantage being that the process was slower than intended; it took some victims 20 minutes to die, and that result didn’t please the military officials. Second, the yellings and the cries for help could be heard far away, disrupting their operation as they might be exposed. Although Gas Vans killed more than 10,000 civilians, German police and the SS quickly shut down the operation due to its major flaws. After the Nazis invaded the Soviet Union June 22, 1941, Nazis took advantage of the sudden invasion of the Jewish population. Once being held as captives, victims were forced to surrender all their belongings and remove their clothing, which would be reserved for the Germans and its collaborators. Then, the SS marched the victims into either forests, ravines, or somewhere from the population. One French escapist said, “They took them here, as they could kill them quietly and discreetly, without fear of rescue attempts” (Henry Samuel) All victims killed by the firing squad were detained as they got shot multiple times by the well-trained SS. SS individuals were trained to aim from the heart to the head and due to this training, victims were instantly killed after lethal bullets penetrated their bodies. In most cases, victims had their faces masked, but in rare cases, victims had no covers, watching himself or herself die as bullets race towards their body. (Wikipedia Contributors) Due to the task, they were asked to carry out, many SSs received traumatizing effects, leaving them mentally scarred for the rest of their lives. Many operations that involved killing among the population soon had an effect on the soldiers and workers that worked there. This is why the Nazis decided to go for a less-killing but a more-abusive method to benefit their country. Concentration Camps, the biggest operation the Nazis carried out, involved more abusive treatment, such as making their prisoners slaves rather than wiping out groups of people. Camp prisoners were often forced to work in stone quarries, coal mines, and construction labor. Also, they were forced to work under harsh conditions that lead them to injuries, illness, or death. For example, at the Mauthausen camp, prisoners were forced to run 186 steps out of a stone quarry while carrying heavy boulders. Once prisoners were unfit for work, they were either deported to a killing center or gassed right away. Concentration camps like Stutthof, Mauthausen, Sachsenhausen, and Ravensbrück, were not designed as killing centers, also had gas chambers. The gas chambers were relatively small, constructed for prisoners that deemed that they were unfit for jobs. (USHMM) As World War II broke out in 1939, despite the need for more labor, the SS authorities continued to mistreat and undernourished the prisoners. And because of this treatment, the mortality rate reflected upon it. By the end of the war, 22 main concentration camps were established, together with around 1,200 affiliate camps, and thousands of smaller camps. (Projetaladin)An estimate of six million Jews was murdered by Nazis, and they never found their liberty. These six million Jews were treated and murdered in such an inhuman way that some operators became traumatized. They were undernourished, mistreated, and often, beaten to death. Furthermore, millions of innocent Jews were sent to Killing Centers to be gassed to death, using an ingredient that leads to suffocation once breathed in, Zyklon B. As Churchill stated, “None has suffered more cruelly than the Jew the unspeakable evils wrought upon the bodies and spirits of men by Hitler and his vile regime. The Jew bore the brunt of the Nazi’s first onslaught upon the citadels of freedom and human dignity. He has borne and continued to bear a burden that might have seen beyond endurance. He has not allowed it to break his spirit; he has never lost the will to resist. Assuredly in the day of victory the Jew’s suffering and his part in the struggle will not be forgotten.” (Gilbert) The experiences that many Jews faced was beyond endurance but they continued to live with the hatred and mistreatment. Millions of Jews died in unimaginable ways under Nazi persecution and their struggle to fight for their freedom will not be forgotten.