Silo Twelve collapsed and was terminated after its airlock opened; Donald continues to remember its residents dying outside.
Solo identifies Silo Twelve on the silo map. Its collapse occurred during Troy’s shift, after two years without a cleaning and with a most recently recorded fear index of eight. Its radio links to other silos were cut as the crisis unfolded. Crowds fled outside and collapsed, clawing at their faces and throats; some tried to get back inside.
Donald Keene remembers a troubled boy among the servers as having brought about its destruction. He recalls terminating the silo after its airlock was opened, marking it out in red ink and receiving no answers to later calls. He said there would be no future generations. The memory remains with him: he again recalls its people emerging and dying outside.
A lost silo whose termination remains a defining memory for Donald.
Also appears in books you've already read — spoiler-safe to their endings: