If one of our on-site tapes gets physicaly destroyed, what should we do??

We know we can re-create the data on it from the off-site tapes - but we
only want to do that if someone needs to do a restore of the data.

If we run a DEL VOL xxxxxx DISCARD=YES that will get rid of the data from
the database..... Does this mean that any data that used to be on the tape
and is still available on the client will be re-copied the next time a
backup runs??

Cheers, Chris