unxv of BBB-eMMC-flasher-2013.06.20.img.xz results in "Unexpected end of input" error

I’m used the command below to decompress the BBB eMMC flasher and got the error "Unexpected end of input’. Does the file need to be updated, or am I doing something wrong?
$ unxz BBB-eMMC-flasher-2013.06.20.img.xz
$ unxz: BBB-eMMC-flasher-2013.06.20.img.xz: Unexpected end of input <----- error

BBB-eMMC-flasher-2013.06.20.img.xz was downloaded from here: http://beagleboard.org/latest-images


I suggest you use the latest image, the one on the Wiki. The website is out of date.