A young Egyptian flees from the horror of the Rabaa Massacre. By Mosa'ab Elshamy. From his Flickr Account. Taken on August 14, 2013. Used with Permission. One year ago today, the world watched in horror as one the single bloodiest days in modern protest history took place in Cairo, Egypt. On August 14, 2013 Egyptian security forces opened fire at a sit-in protest in Rabaa Al Adawiya Square, killing more than 800 people opposed to the ousting of Egypt's first democratically-elected president Mohamed Morsi. A few weeks earlier the reign of Morsi, a senior Muslim Brotherhood member, was cut short after only one year in power. Morsi's ouster was announced on July 3 2013 by the head of the Egyptian Armed Forces Abdel Fattah El Sisi, who later became the president of Egypt. Al Jazeera Plus shared this 23-second video, featuring photographs taken by Award-winning Egyptian photojournalist Mosaab Elshamy touching on the scale of the catastrophe. Elshamy shares an extensive gallery of photographs from the Rabaa massacre and its aftermath on Flickr. [Warning: Some pictures, particularly of corpses in the morgue, are graphic]. His gallery of 184 photographs have had almost 363K views to-date. Raba'a's victims. By Mosa'ab Elshamy. From his Flickr Account. Taken on August 14, 2013. Used with Permission. In a series of tweets on August 14 last year, he describes how he dodged bullets: Literally felt a bullet pass over my shoulder. Heard a buzz similar to that of a gigantic mosquito traveling at the speed of light. Eerie. — Mosa'ab Elshamy (@mosaaberizing) August 14, 2013 Today he writes: A year later the magnitude of killing in Rabaa is more realised and the mourning & condemnation seems louder. Not in vain. — Mosa'ab Elshamy (@mosaaberizing) August 14, 2014 And like many, ElShamy wonders if justice will ever be served. He notes: A year later a monument honouring police and military stands in the same place where hundreds of civilians were massacred. — Mosa'ab Elshamy (@mosaaberizing) August 14, 2014 Remembering the Raba'a massacre While many Egyptians were happy with the overthrow of Morsi and his Muslim Brotherhood junta, others were upset that Egypt's first democratically elected president had to go following a “coup.” What followed next, particularly the Raba'a massacre, changed the euphoria many had earlier expressed. Basil Dabh sums up the sentiments many feel in less than 140 characters: I hope we never see another day as dark as August 14, 2013. Over a thousand killed, dozens of churches burned, people cheering loss of life. — Basil الضبع (@basildabh) August 14, 2014 Egyptian Hatem wonders: حد يفهمني كده : ازاي الاف الأسر و الاهالي هيعيشوا و يتعاملوا مع دولة جيشها و امنها قتل اولادها و افراد من عائلاتها ؟؟؟ — Hatem (@QALAWA) August 14, 2014 Can someone explain to me how thousands of families and relatives can live with and interact with a country whose army and security forces have killed their children and members of their families?? Mayhem at Rabaa. By Mosa'ab Elshamy. From his Flickr Account. Taken on August 14, 2013. Used with Permission. HRW report on Raba'a According to Human Rights Watch, the massacre was “all according to plan.” A 188-page report released to mark the anniversary “documents the way the Egyptian police and army methodically opened fire with live ammunition on crowds of demonstrators opposed to the military’s July 3 ouster of Mohamed Morsy, Egypt’s first elected civilian president, at six demonstrations between July 5 and August 17, 2013. While there is also evidence that some protesters used firearms during several of these demonstrations, Human Rights Watch was able to confirm their use in only a few instances, which do not justify the grossly disproportionate and premeditated lethal attacks on overwhelmingly peaceful protesters.” The report, which took one year to investigate, describes the killing of at least 1,150 demonstrators by Egyptian security forces in July and August last year as “systematic and widespread” saying that the killings “probably amount to crimes against humanity.” HRW adds: In the August 14 dispersal of the Rab’a al-Adawiya sit-in alone, security forces, following a plan that envisioned several thousand deaths, killed a minimum of 817 people and more likely at least 1,000. “In Rab'a Square, Egyptian security forces carried out one of the world’s largest killings of demonstrators in a single day in recent history,” said Kenneth Roth, executive director of Human Rights Watch. “This wasn’t merely a case of excessive force or poor training. It was a violent crackdown planned at the highest levels of the Egyptian government. Many of the same officials are still in power in Egypt, and have a lot to answer for.” By Mosa'ab Elshamy. From his Flickr Account.