My Book becomes empty after unlocked

While I was transfering a file to My Book, it stoped at 99%. The light did not flash any more and the computer hanged.
After rebooting and unlocking, I can see all root directories but all of them become empty. However, the unlocked drive is recognized by Explorer, Diskcheck and all other softwares can not identify it, including WD’s own utilities. I also tried Filerescue Pro and Partition Magic, none of them see the unlocked drive.
Please help!


Another options you can try are Recuva and TestDisk

the best part is that they are freeware

No, neither of Testdisk nor Recuva can identify the drive.
Even WD Smartware can not see it, although the drive and unused space are correctly displayed after unlocking.