Robert Davis describes how he recovered from accidentally deleting a production-necessary LUN:
That’s right, I did it. I was deleting unused LUNs and the focus somehow jumped from the LUNs for the one database onto a LUN for another database. I blame an errant mouse-click. As soon as I deleted the LUN, I realized the name was wrong. The LUN held the log file for a production database.
Fortunately for me, the database was in an Availability Group so after recreating the LUN and attaching it, I restored the database from the read-only secondary.
The biggest disservice you can do to yourself in a situation like this is to panic. Stop, think it through, and act once you have a plan. Even better, plan ahead: try one of these disasters in a non-production environment and see how the team reacts, what you need to do to bring it back up, and how you can improve next time (which might be in prod).