In case anyone was curious, this paragraph

> After the bombing ended, US Special Forces and Dostum’s troops herded 3,000 surviving prisoners into sealed metal containers and drove them for 20 hours to Sheberghan prison. Most of the prisoners suffocated along the way. When the convoy arrived at its destination, the containers were emptied and the prisoners who had survived the journey were shot. Their remains were buried in a mass grave.

presumably refers to the following event: https://en.wikipedia.org/wiki/Dasht-i-Leili_massacre