How to kill a bad write process in lubuntu

[Linda]

I had a usb drive that went bad so when I tried to do a cp 
command it just hung doing nothing.  I killed the command 
with ctrl -c but it was still listed when I did ps -aux. I 
tried to kill the process but it was stat D and I could not 
kill it. I tried doing a forced umount of the usb drive. The 
process was still there.  Did a shutdown but it would not 
finish shutting down and I had to turn off the power. Then 
this week I tried to copy a file that was too large for the 
usb drive this time using pcmanfm instead of the command 
line. Although it told you out of space and had a stop 
button it did not stop the process and again had to do a 
hard reboot to clean up the filesystem.
Is there a better way to clean up a write process that has 
gone bad
               Linda