When Myanmar's military seized power in a Feb. 1 coup, millions across the country took to the streets in protest. The Myanmar military responded with weapons of war and brutal, premeditated counterinsurgency tactics against demonstrators. U.N. officials and human rights groups say these acts must be investigated as crimes against humanity. Noise from the nearby pagoda roused Aung and his family before dawn on April 9. He saw dozens of soldiers shouting and cursing as they streamed onto trucks, rifles slung across their chests. By the end of that day, the Myanmar military, known as the Tatmadaw, and police officers had killed at least 82 people, according to groups tracking protest deaths making it the deadliest single crackdown since the military seized power. A Washington Post investigation of that day's events reveals the use of counterinsurgency tactics, specialized military units and military-grade weaponry against civilian protesters " resulting in a high number of casualties. "It is very systematic [and] the pattern of violence is very, very clear," said Tom Andrews, the United Nations' special rapporteur for Myanmar. "These are crimes against humanity," he said, noting especially the premeditation before the attacks in Bago. Zaya, a front-line protester ... said he and others there heard the sounds of heavy weaponry. [A] wall, which withstood gunfire for hours, began to shake and collapse. Soldiers then rushed forward ... shooting indiscriminately. "They were killed like goats in a slaughterhouse," he said.