On November 2, 1982, a truck explodes in the Salang Tunnel in Afghanistan, killing an estimated 3,000 people, mostly Soviet soldiers traveling to Kabul.

The Soviet Union’s military foray into Afghanistan was disastrous by nearly every measure, but perhaps the worst single incident was the Salang Tunnel explosion in 1982. A long army convoy was traveling from Russia to Kabul through the border city of Hairotum. The route took the convoy through the Salang Tunnel, which is 1.7 miles long, 25 feet high and approximately 17 feet wide. The tunnel, one of the world’s highest at an altitude of 11,000 feet, was built by the Soviets in the 1970s.

The Soviet army kept a tight lid on the story, but it is believed that an army vehicle collided with a fuel truck midway through the long tunnel. About 30 buses carrying soldiers were immediately blown up in the resulting explosion. Fire in the tunnel spread quickly as survivors began to panic. Believing the explosion to be part of an attack, the military stationed at both ends of the tunnel stopped traffic from exiting. As cars idled in the tunnel, the levels of carbon monoxide in the air increased drastically and the fire continued to spread. Exacerbating the situation, the tunnel’s ventilation system had broken down a couple of days earlier, resulting in further casualties from burns and carbon monoxide poisoning.

It took several days for workers to reach all the bodies in the tunnel. Because the Soviet army limited the information released about the disaster, the full extent of the tragedy may never be known.