With no warning my mom sims died of laughter. I am so mad.

I've recently had this happen to the matriarch of my 100 Baby Challenge, luckily she had just had her last kid, but that meant the new matriarch was a 1 day old baby raised by her sister.

I had recently installed the Slice of Life mod and I found my Sims were constantly "Hysterical" due to a personality trait. I'm sure they're still ironing out that system but for now I uninstalled it.