As an example, Equinix in Chicago failed back in like 2005. Everything went really well, except there was some kind of crossover cable between generators that helped them balance load that failed because of a nick in its insulation. This caused some wonky failure cycle between generators that seemed straight out of Murphy's playbook.
They started doing IR scans of those cables regularly as part of their disaster prep. It's crazy how much power is moving around in these data centers, in a lot of way they're in thoroughly uncharted territory.