Here’s how to open a can in an emergency (this is so simple!)

Just rub the top of the can against the concrete to wear away the rim of the lid.
When enough of the rim is gone, which you can tell if you see moisture on the lid, wipe off any filings, then squeeze the can, and the lid will pop off.
This technique takes a little strength and a little patience!
Of course, the smartest thing to do is plan ahead and make sure you include a manual can opener in your shelter-in-place kit. But if a zombie apocalypse or camping mishap takes you by surprise, you definitely don’t have to starve.