SD card corrupt after hot removal Accidentally removing a card reader without first ejecting the Sandisk 256GB MicroSD in it has caused the SD card to become corrupt. When inserting it now, OSX prompts that it cannot read the card and offers an option of initialising it. This doesn't work, and Disk Utility gets stuck "waiting for the disk to re-appear" when I try to format it.
In Disk Utility and in /dev list, the card shows up as 8MB rather than 256GB. I am hoping that I haven't damaged the controller and that the card might be fixable. Any thoughts?
Just setting up a new volume is pretty easy with:

diskutil eraseDisk ExFAT SD256 disk44


(I chose disk44 above for the example but you will need to choose your disk number after making sure you're not erasing the boot volume or other critical disks - check your backups and disconnect any external drives you aren't prepared to restore from backup)

See Cannot unmount disk0 resource busy and When erasing media in Disk Utility, how can I change the default format? for a little extra visual or other options of diskutil that work on a volume instead of destroying all data on the disk.