Core stopped and wasn't restarted

This morning I woke up with Home Assistant being unresponsive. Luckily I could SSH in and this was the latest in the core logs:

s6-rc: info: service legacy-services: stopping
[23:53:13] INFO: Home Assistant Core finish process exit code 0
[23:53:13] INFO: Home Assistant Core service shutdown
s6-rc: info: service legacy-services successfully stopped
s6-rc: info: service legacy-cont-init: stopping
s6-rc: info: service legacy-cont-init successfully stopped
s6-rc: info: service fix-attrs: stopping
s6-rc: info: service fix-attrs successfully stopped
s6-rc: info: service s6rc-oneshot-runner: stopping
s6-rc: info: service s6rc-oneshot-runner successfully stopped

Strangely no error before this. Why would it shut down? And why wasn’t it restarted? I tried checking the supervisor logs as well, but they don’t stretch this far back for some reason.

I was able to bring the system back up with ha core start.