About 10 years ago, Stanford Univerity had a major outage that was caused by a rat chewing thru a 12kv cable.
The university is fed by dual 60kv feeders from 2 different PG&E substations, feeding 2 60kv->12kv transformers, and a 60kv->4kv transformer. Either feeder can handle the entire campus load.
There is also a cogeneration facility on campus, which can handle most of the load for the core campus and medical center.
Unfortunately, the rat chewed up the 12kv intertie between the substation and the cogen facility, and there was no way to isolate it, so most of the campus was shut down for about 12 hours.
The entire campus went down at once, but they were able to restore power to the older 4kv system by feeding it directly via the 60kv->4kv transformer, but because the 12kv intertie was down, the entire 12kv distribution was shut down until repairs were made.
They subsequently installed some additional switches to allow the 12kv intertie to be isolated, and they might have installed a second parallel intertie as well.
There was a lot of fallout from this incident, as the outage took down the datacenter, with the mainframe computer that was used for hospital patient care records, as well as the mainframe used for campus business services, and the mainframe used for the research libraries group.
In addition, the datacenter housed the NSFnet router feeding most of the internet in the greater bay area at the time, as well as the BARRnet routers feeding other internet sites in the bay area. This was before the commercial internet existed as we know it oday, so during the outage, most of the bay area was offline, with the exception of a few sites that were connected to other networks.
The good thing is that the emergency power systems at the campus radio station where I was working at the time all functioned properly, and there was no interruption of service.
As a side note, during the 1989 Loma Prieta earthquake, we were one of the only radio stations in the bay area that never went off the air, since we were relatively low power (500 watts), and our transmitter was backed by a UPS and a generator.
The studios were backed by a inverter fed from a battery bank that also fed the station PBX, as well as a generator. We also had a portable generator that could be connected to feed limited lighting and the battery chargers, as well as the inverter fed emergency power system that fed the studio electronics.
