Originally Posted by nealtw
Is it frozen under the floor, in the outside wall
Not in Ft. Lauderdale...
Turn off the valve then turn it back on.
If the tank fills one time then goes back to not filling and you have a Fluidmaster fill valve then replace the fill valve and supply line its shot.
Also another possibility is that you have a Watts Floodsafe supply line and it has nuisance tripped. Get rid of it and install a regular braided stainless steel supply line without the Floodsafe feature. Trust me you are lucky it didn't fail a different way...