That is terrible. Is there anyone that lives near or works at the PO that could take care of them for a day or so if you let them know? This of course is conditional upon them actually getting delivered. I know that our PO would at least heat, feed, water them to keep them alive if you give them permission to do so. It made national news a couple of weeks ago in New York when a box of chicks was misdelivered. I would call the post office.
I talked the PO. They are going to ask all their drivers as they come back in today if one of them can care for the chicks overnight. I can only hope someone at least opens the box to give them water. Poor poor new line CCLs (16 of them!).