If this drive is being used with windows, it should be formatted as FAT32. Otherwise the windows computer won't be able to see the drive.
Did you unmount the drive before you unplugged it? That's one thing that can cause a drive to crash. Or it may have crashed for any number of other reasons.
On location, I kept 2 sets of drives, the drives I worked from & a backup set that was mirrored from the main set of drives. That way if a drive failed, I could format it & copy back the data from the backup drive without fear of loosing any work or very much time.
The one time a drive did fail on me, I was able to recover the drive with Disk Warrior. The whole process from rebooting the mac to finishing up with Disk Warrior took maybe 5 or 10 minutes.
Arnie
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Peristroika, a film by Slava Tsukerman
http://www.arniepix.com/blog