OS X Disk Utility to Repartition USB External Hard Drive but froze and Force Quit Disk Utility and Now Missing Disk Space

Had to use

fsck_hfs -r /dev/disk1s3 (disk1s3 is EXAMPLE only)

OS X: repairing an external USB drive that won’t mount

If you have an external USB drive, you have to unmount it first. You can find the name of drive by going to Disk Utility and Get Info on the partition.