Although a power outage is virtually impossible for the Non-Euclidean Coalition, this is the Foundation, equipped with backup power and generators to counteract that one-in-several-million chance. The moment the power went out, these systems automatically activated, maintaining normal operations in the underground containment chambers. For a short while after, they could even supply the remaining essential facilities.
However, the building was simply too large, and distributing power throughout took some time. This brief period was enough for Chen Xiao and his team to accomplish quite a lot.
First and foremost, they needed to gain entry to the building, which, being a building, always has doors...