Beslan school massacre

This may be a few years old, but incredibly horrifying and relevant.

On September 1, 2004 children attending school in Beslan, Russia were accompanied by their parents and other relatives for ceremonies hosted by their school to celebrate the commencement of a new school year.
At 09:30 local time, a group of several dozen heavily-armed rebel guerrillas wearing military camouflage and black balaclava masks, and in some cases wearing explosive belts, arrived at the school in a stolen police GAZ van and a GAZ-66 military truck.
The attackers proceeded to take approximately 1,100 to 1,200 hostages from the children, parents, and teachers present. They herded the hostages into the school's gym, and confiscated all mobile phones under the pain of death. They ordered everyone to speak in Russian and only when spoken to; when a father named Ruslan Betrozov stood to calm people and repeat the rules in the local language, Ossetic, a gunman approached and killed him with a single shot to the head.
The attackers then singled out 17 of the strongest adults who represented a threat and took them into another room on the second floor. There, they shot them with automatic rifles, killing all but two. The militants then forced other hostages to throw the bodies out of the building and to wash the blood off the floor.
The standoff ended when an explosion went off in the gymnasium and hostages fled, while hostage-takers opened fire on the children and rescue workers. Russian troops, who had not planned to storm the building, returned fire. Several hours later the scene remained in chaos, with troops fighting room-by-room. In the end, over 350 hostages were killed, including 186 children.
The crisis followed a bloody week in Russia. A female suicide bomber killed nine people outside a Moscow subway station Tuesday. Two suspected Chechen female suicide bombers downed two airliners on August 24, killing all 89 people aboard the planes.
Shortly after the crisis, official Russian sources stated that the attackers were part of an international group led by Basayev that included a number of Arabs with connections to al-Qaeda, and said they picked up phone calls in Arabic from the Beslan school to Saudi Arabia and another undisclosed Middle Eastern country.