Determine shutdown cause - eviltoast

Hi all, I’ve got a cheap Celeron box running OPNSense and it’s been pretty good so far, but I found twice that the device turned off at some point while I was at work, and I have been unable to figure out what’s causing it.

The only change was that I enabled Monit to see if I could figure out what was causing crowdsec to stop sometimes but never ended up configuring anything. I’ve only been running it for a couple months though, so it’s possible that that is not related.

I know that on a Mac (based on freebsd, right?) you can determine whether the shutdown reason was a hard shutdown, regular shutdown, or the power cable being unplugged. Is it possible to do that with OPNSense? I’d like to narrow it down to software or hardware ideally.