So I was making a bootable drive for El Capitan on my 16g usb flashdrive when I got an error msg in terminal telling me that it failed. It was weird because the usb was ejected by the OS. When I removed the usb and put it back it showed up as a bootable drive (probably one that won't work given the error msg I got), however it wouldn't let me erase it in disk utility OR TERMINAL. Literally nothing works. I tried every single terminal command I could find on the internet for forcefully erasing a drive but I always get error messages or that the drive cannot be unmounted.
Any help pls I really don't want to trash my usb
Any help pls I really don't want to trash my usb