USB didn't eject properly I think. Tried formatting it and now it doesn't work.

Okay I think a USB drive (Lacie Xtremekey) did not eject properly so I tried formatting it, but that didn't work correctly. The USB was flashing on that computer and then disappearing before I tried formatting it. Now when I try formatting it my computer says it can't open the drive (this is in disk utility). Any ideas on how to fix this?