That would not be a good situation to be in - You should avoid by all means, actions let your customers know what’s going on, clients appreciate being kept in the know.
Next, assess the situation, Is it long lasting or few mins outage, figure out the issue and its impact. Can you use portable generators or temporarily move critical sites to a backup location? If so, prioritize restoring essential services first.
After the outage, share a brief summary with customers about what happened and what steps you’ll take to prevent it in the future. It’s also a good time to seriously consider investing in UPS or other redundancy solutions to avoid this in the long run..
Always use Tier3 or better datacenters - it pays off.
