Was talking to a friend the other day and heard another story of a dog being suffocated getting it's head stuck inside a box. This is at least the 5th one I have heard like this over the years of dogs getting into cereal boxes, cracker boxes, etc. they try to get food out of the box, get their heads stuck and usually are suffocated by the box liner.
Good idea not to leave those things out, even on counters if you have a potential counter surfer.