60,000 prisoners of The Holocaust between August 1943 and March 1945. Conservative estimates assume that at least 20,000 inmates perished at the Mittelbau-Dora concentration camp. In early April 1945, an unknown number of prisoners perished in death marches following the evacuation of prisoners from Mittelbau camps to Bergen-Belsen concentration camp in northern Germany. In April 1945, U.S. soldiers liberated the Mittelbau-Dora concentration camp. Only a few prisoners were still in the camp and the U.S. soldiers found the remains of approximately 1,300 prisoners in the Boelcke barracks. The names of these prisoners are unknown. Mass graves of the dead prisoners from the Mittelbau-Dora concentration camp were dug by German civilians under orders from U.S. soldiers. Soviet mass killings Communist regime massacres in Yugoslavia Bleiburg repatriations Communist purges against Hungarians and Germans in Serbia in 1944-45 Barbara Pit massacre Mass graves in Slovenia Srebrenica massacre Victims of the Srebrenica massacre were murdered by the Army of Republika Srpska and buried in mass graves. Serb forces used mass graves throughout the Bosnian War and thousands of victims remain unidentified as of 2017. Famine The Great Famine Ireland's Great Famine lasted from 1845 to 1849, a period wherein about one million people died. Because of the excessive number of deaths and extreme poverty, many families were unable to provide a wake or proper burial for loved ones and used mass graves instead. Archaeological excavations have taken place on Irish mass burial sites. One excavation revealed a mass grave of nearly 1,000 individuals. The skeletons within the grave were layered on top of each other in multiple sub-rectangular pits positioned less than a meter apart. Epidemics and pandemics Bubonic plague The bubonic plague outbreak existed in three pandemic waves and is known as the Black Death. In the 1300s alone, an estimated 20–30 million people were killed in Europe and approximately 12 million people were killed in China. These deaths were at least 30 percent of the European population at that time. The last major outbreak of the bubonic plague occurred in London from 1665–1666 and is known as The Great Plague. In March 2013, a plague pit of 25 skeletons was found in a 5.5 meter-wide shaft during the construction of a new railroad in London. The skeletons were neatly lined up in two rows and were about 8 feet underground. Samples from 12 corpses were taken and forensic analysis confirmed traces of