Your attempt to write files to the disk-drive inside the external case has "failed" -- the data could not _correctly_ be written.
So, if your Passport is still under warranty, exercise the warranty to get it repaired/replaced.
If the warranty has ended, it's possible to disassemble the case, remove the "dead" disk-drive, buy a replacement disk-drive, connect it, and reassemble it, and "reuse" the external case.
Answers & Comments
Your attempt to write files to the disk-drive inside the external case has "failed" -- the data could not _correctly_ be written.
So, if your Passport is still under warranty, exercise the warranty to get it repaired/replaced.
If the warranty has ended, it's possible to disassemble the case, remove the "dead" disk-drive, buy a replacement disk-drive, connect it, and reassemble it, and "reuse" the external case.