Original Commentary
Why Sandra? Not just because she's his sister, but because she's good in an emergency, has a decent chance of knowing it, and, as importantly, because she's one of the few people that he'd admit vulnerability around. She lacks that killer instinct that the rest of their family probably has - Terrence

Modern Commentary
The showerhead detaching is just one piece of this multi-point failure. There's burst pipes. There's flooding. It's a whole mess. Hence the waterline in the third panel - Terrence