Don't know much about Raid 5 or TS but had the odd disk or two fail so sorry to hear that.
Usually one error fails at a time -although this isn't always true for a power cut or say a cup of coffee poured in.
Anyway, before wiping data is there a way of finding out how many disks/stripes went down - if only one it should still be able to recover something -no?http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks#RAID_5
mentions a 'write hole' vunerability in RAID 5
I can see its tricky/impossible? to recover data by one pulling out the disks individually and connecting each HD into a PC since its striped.