Today's Wall Street Journal leads with an important article on a terrorist attack on an electric power substation. When I started to read the article, I wondered if they were describing an exercise or simulated attack. They weren't. A team of terrorists attacked a PG&E substation in Silicon Valley. They cut communication lines, then used rifle shots to puncture the transformer vessels and drain them of their cooling oil. The transformers promptly overheated. The terrorists got away just before the police arrived. Whoever did it was well-trained---their rifle cartridges didn't have fingerprints.
This attack is disturbing on a number of levels, of course. One cyber-physical angle is that, although this was primarily a physical assault, they also attacked the communication links into the substation as preparation. It appears that communication was at least close to being a single point of failure in the system. Monitoring the status of communication clearly helps with terrorist attacks such as these and it can also help contain other types of non-malicious faults.
I commend the Wall Street Journal for bringing this event to the public's attention.