Donald describes bombs designed to collapse silos if other controls fail; he says collapse codes failed against silos that went dark.
Donald describes a final means of destroying silos whose inhabitants overcome the other controls: bombs intended to bring the structures down.
He now explains that the thick concrete floors were designed to make demolition possible. The system’s ability to enforce control has limits, however: according to Donald, collapse codes failed against the group of silos that went dark.
According to Donald, the system uses bombs and depends on the silos’ thick concrete floors being designed for demolition. The bombs’ physical appearance is unspecified.
A destructive fallback intended to defeat communities that overcome the other silo controls. Donald reports that its collapse codes have already failed against a group of disconnected silos.