"Military Style" Raid on California Power Station

I don't know what to think about this:

Around 1:00 AM on April 16, at least one individual (possibly two) entered two different manholes at the PG&E Metcalf power substation, southeast of San Jose, and cut fiber cables in the area around the substation. That knocked out some local 911 services, landline service to the substation, and cell phone service in the area, a senior U.S. intelligence official told Foreign Policy. The intruder(s) then fired more than 100 rounds from what two officials described as a high-powered rifle at several transformers in the facility. Ten transformers were damaged in one area of the facility, and three transformer banks -- or groups of transformers -- were hit in another, according to a PG&E spokesman.

The article worries that this might be a dry-run to some cyberwar-like attack, but that doesn't make sense. But it's just too complicated and weird to be a prank.
Anyone have any ideas?