Depends on if they’re being asked to perform any duties. They could be told “you’re off work. Do what you want” and they’re stuck there just like the customers, not being paid. If they’re being asked to help people, that’s kind of a grey area of it not being “store functions” and just being “we’re all community trying to deal with a disaster and you have helpful knowledge/skills for this situation”.

Really depends on what’s going on/how things are being said.