Minor liner problem

Oh well...I knew it was going too well....pool is full and one of the corners which had yet to be fastened down.... please dont ask...blew up in the wind...went in the pool....nobody was looking and we got some water behind the liner and washed the sand out of a small section along the wall....about 6 ft down one wall....what now? Is there a way to fix it?

Can you pour something behind the liner that will fill the gaps?

I know everybody with any sense is not still building their pool....they are in them where they belong.

Sorry for the double post....