The Beslan siege stretched across three days. It ended around 1 p.m. on Sept. 3, when two powerful explosions were set off in the gymnasium, blasting a hole in the wall through which several hostages tried to escape. Militants fired on them before exchanging gunfire with the security forces, who were then ordered to storm the building.

The militants rounded up the surviving hostages, about 300 people, and forced them to go to other parts of the school, while dead, wounded and traumatized hostages stayed in the gymnasium.

Flames spread, and the roof collapsed around 3:30 p.m.

In all, more than 330 people were killed — including 12 members of the security forces — and hundreds of others were wounded. One militant was captured, and the rest were killed.

The security forces were armed with tanks, rockets, grenade launchers, flamethrowers and other weapons. The court found that the use of such lethal force “contributed to the casualties among the hostages” and violated the “right to life” by failing to restrict lethal force to what was “absolutely necessary.”

The court also found that the operation’s command structure “suffered from a lack of formal leadership, resulting in serious flaws in decision making and coordination with other relevant agencies.”

The court said that the Russian authorities had fallen short on their obligation to protect life. “The security arrangement at the school had not been heightened; the local police had not taken sufficient measures to reduce the risks; no warning had been given to the school administration, or to the public attending the ceremony; and no single sufficiently high-level structure had been responsible for the handling of the situation,” the court found.