SRS, the "bearproof" cans the city of Juneau uses are heavy gauge steel square jobbies that have inset square lids whose catch is recessed; it is not possible to lift the lid until the catch is released.

Dumpsters, on the other hand, are not bear proof, only with a tight lid that discourages the effort needed to get inside.

If cans and dumpsters are overflowing, of course...

BTW, I was misleading in saying there is NO record of actual attacks on humans- I was speaking of Juneau in recent years. I know that in 1959 there was an attack by a black bear on a man with severe consequences and I read in an old newspaper that in 1928 a brown bear attacked and hauled off a miner in a then-unsettled area of Juneau.

And of course in other areas of southeast Alaska there are horror stories of deer hunters being killed by browns. In 1990 it happened on Admiralty Island to the son of a man I knew.

As for bells to advertise one's presence to bears- a Tlingit friend told me that when the bears hear a bell, they tell each other: "Dinner!" ;)