Played Sims Dying During Rotational Play

Oh, and here I thought it was just me. One of my teenage Sims ended up dead outside a gym while I was playing another household. I didn't even realize there was something going on. When my Sim stepped outside, there was a small crowd, a Sim covered in ice and Grim preparing to reap that Sim. When I hovered the mouse over that icy Sim, I realized it was one of my teenagers from my main household, then Grim swung his scythe and the game asked me what I wanted to do with the teen's inventory. I quit and restarted the game because if that kid really has to die, he'd better do it while I'm playing his household so his parents get to give him a proper farewell.

I've never had this issue before, story progression is turned off, neighbourhood stories are active only for NPCs but not for a single one of my households. No idea what happened there or why all of a sudden all NPC Sims decided that being out and about in t-shirts and shorts during a snow storm was a bright idea.