Is it reasonable to assume a Safeway that was rebuilt 10 years ago has a diesel generator?

I ask this because there was a major power outage here last night. It lasted about 10 hours. Long enough I tossed everything in my fridge except the butter.

Safeway also lost power. I just wonder if it reasonable to assume they had a back-up to keep the freezers and fridges running.

I need to go replace what I lost but not sure if I can trust what they are selling.