It's actually something we need to take seriously. My best friend dropped dead instantly with no prior symptoms one day and getting things straighted out took a while.
Just in the past month at work we've had one death, one emergency surgery, a spontaneous abortion, and a guy diagnosed with multiple cancerous tumors. That's not normal here, but it does illustrate how things can happen abruptly.
I keep a little contact list for my wife to use in case I can't communicate anymore.