Failed FrontView backup, how to fix?

After more tests and some back and forth with Mike from CCC, I've narrowed it down to two corrupt directories inside the directory I want to delete. They throw an I/O error when I touch them in any way.

When I run a Filesystem check on the USB drive from the drop down menu in FrontView, I get a report that there were problems found and corrected. But I'm still unable to delete the corrupt directories.

I'm wondering if fsck would fix the problem? Is there any way to run fsck on the USB drive from terminal? Right now it won't run because the volume is mounted. Is there a command that will unmount /dev/sde1 but leave it attached so I can run fsck?

Thanks!

ReadyNAS_Pro:/USB_HDD_2/Epocrates/production/FCPX Libraries# mount
/dev/md0 on / type ext3 (rw,noatime,nodiratime)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw)
tmpfs on /ramfs type ramfs (rw)
tmpfs on /USB type tmpfs (rw,size=16k)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/c/c on /c type ext4 (rw,noatime,nodiratime,acl,user_xattr,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1)
/c/Production on /home/ftp/Production type bind (rw,bind)
/c/Projects on /home/ftp/Projects type bind (rw,bind)
/c/Transfer on /home/ftp/Transfer type bind (rw,bind)
/dev/sde1 on /USB/USB_HDD_2 type ext4 (rw,noatime,barrier=1,acl)
ReadyNAS_Pro:/USB_HDD_2/Epocrates/production/FCPX Libraries# fsck /dev/sde1
fsck 1.42.12 (29-Aug-2014)
e2fsck 1.42.12 (29-Aug-2014)
/dev/sde1 is mounted.
e2fsck: Cannot continue, aborting.


ReadyNAS_Pro:/USB_HDD_2/Epocrates/production/FCPX Libraries#