My OS-X keeps busting disks



I have a Mac OS-X Server v10.2 @ my job, and for the last 5 months, I've had 7 (yes, seven) disks busted. In four of the situations it was the PSU on the external disks, in two others it was the disk physically, and this morning it seems that the filesystem on the last disk is wasted - the Server doesn't even see the disk.

Anyone seen anything like this, and is there anything that could do these things to a disk, i.e. the SCSI card ect.

BTW, I am running Helios OPI on the server....

Thanx in advance :)
a friend of mine bought a NEW 80 gig drive, formatted it with the MacOS 10.0.4 installer, copied all his vital data over there and formatted the old drive. While he was setting up the new backup server for the files, the drive died! Physically! He tried EVERYTHING (all his vital company data was on the drive...he was just configuring the backup server for the data.....), every HDD tool he knew but the drive was dead.