It's always funny to me that Americans think Emus are dangerous when in Australasia they are commonly just kept in walk-through enclosures because they are so harmless.
Anyway, here are a couple of cassowary enclosures I've seen which are a bit worrisome. The first is at Songkhla Zoo in Thailand (the fence is at the cassowary's chest-height when it is standing upright), and the second is at Taiping Zoo in Malaysia (the fence is inward-facing, but I reckon a cassowary could clear it easily if it wanted).