Where is update.zip located on the phone once it has been downloaded

[hput3]

I finally finished the 725MB download for the new update named update.zip.  I saw it say the files address but only

remembered the last few bits once I got to where I could write it down '.../cache/fota/update.zip'.  But, now I cannot

find it.  The update failed.  I hope I don't have to download the whole 725 MB again.

Anyone know where the update files should be on my file system?