牢獄之災

牢 = 宀 + 牛 : Sir Lancelot (l) keeps a bull (牛)in the aorta's kitchen (ao2) by imprisoning (牢) it in a very sturdy (牢) graduation cap (宀).

狱 = 犭 + 讠 + 犬 : Yu the Great (yu) opened an animal shelter in the space station's bathroom (Ø4), and she put up an advertisement column (讠) with the faces of her dachshund (犭) and her Saint Bernard dog (犬). For the dogs however the animal shelter is more like a prison (狱) because they are kept in small cages.

之 = 丶 + Z : Mnemonic symbol: Sooo sleepy... "zZz" (the character looks like a "Z"). James II of England (zh) fell asleep in front of the space station (Ø1). He sleeps on a big petal leaf (丶), making loud "zZz" (之) sounds.

灾 = 宀 + 火 : Zorro (z) just earned his PhD and is celebrating it with a bonfire (火) in front of the airplane (ai1), but then he accidentally drops his graduation cap (宀) and his certificate into the fire! What a disaster (灾)!