Being that a lot of security is run over the phone with backup over cell (cell service was also effected by this), one has to wonder if this might not be robbery related.
It would have to be an extremely astute robber to do it this way. The robber would have to know which cable protected his target and whether it was copper or fiber fed and have the knowledge of any diverse ring applications. In short, I doubt the robbery theory since the damage was in a manhole and the robber would have had to have knowledge which sheath held both the protection circuit, as well as the cell sites for the entire area.
·