Baffling that they couldn't have a diesel generator handy. One can rent an inverter, like for portable lighting units or a Lincoln welder, pretty readily and for relatively inconsequential sums in most cases.
Sadly you need to plan for these well in advance and be willing to sink significant resources.
Possibly this is a case of California climate biting them. A lot of the big research universities in the Northeast have steam plants, originally for heat, but often with cogen facilities as well. Usually not much, a meg or two, but it is something.