Fortunately, the generator kicked in, so my lights stayed on. But all the “in-store” music and announcements were stopped, and all non-essential things, etc.
But it occurs to me that not all truck stops have a generator. Surely, someone has been in the shower when it went completely dark. Can you imagine feeling around in a strange place, naked, trying to find your phone? Or the door? Or what if it was before cell phones? What’s the protocol for this?

