Left Jerry can in the shed, now it looks vacuumed. Why?
Basically I filled up a Jerry can to have some extra stash of fuel for my motorbike. I stored it in the shed and I honestly kind of forgot about it because things happened and I didn't get to use my motorbike for awhile. Forgot about it for like 1-2 months. Now the Jerry can look like it's vacuumed or has been sucked out of air. Why does this happen? Is it safe to be kept in the shed?
Enlighten me please, thanks :)