This sentence kind of implies that foreign actors committed the attack, but a leftist group took credit for it[1].
[1]: https://www.rbb24.de/panorama/beitrag/2026/01/berlin-suedwes...
Last time I knew of an attack like this in Berlin, it was a direct retaliation after the government attacked their house with military tanks.
Which is a good thing. Few people deserve that long in prison.
Some substations don't have redundant feeder power either, although that's more often the case where geography makes it difficult (islands/peninsulas)... But the mention of wiring on a bridge might be an indication that is a geographically difficult area of Berlin?