Tinned food lasts ages and won't go to waste if it all pans out to be fear mongering. Water containers (large ones) can be filled quickly if the SHTF. If anything happens (please just look and use discernment - check it against the Word of God) you won't end up fighting against the mob for that last tin of peas or loaf of bread.
If something really did happen, (and I believe it is inevitable) it would be fair to say it would happen so quickly, sooo fast, it will take peoples breath away, and what would all the mockers and scoffers say then? Complain that nobody told them that's what.
PLEASE READ THE BIBLE. USE DISCERNMENT. CHECK WORLD EVENTS AGAINST THE WORD OF GOD. TURN TO CHRIST AS THE ONLY WAY TO SALVATION.
That is why He came in the first place - for YOU!