I suspect some update was downloaded and automatically installed. I see via router logs that there was little network traffic all day, until 90Mb downloaded right around 5pm. Since then, I can no longer reach HA UI, nor connect via ssh. The only log or info I see is the observer log at port 4357 (below). I will try to connect a monitor to the RaspberryPi to see if there is any other info. Anything else I can try before doing a complete new install and restore from backup?
s6-rc: info: service s6rc-oneshot-runner: starting
s6-rc: info: service s6rc-oneshot-runner successfully started
s6-rc: info: service fix-attrs: starting
s6-rc: info: service fix-attrs successfully started
s6-rc: info: service legacy-cont-init: starting
cont-init: info: running /etc/cont-init.d/udev.sh
cont-init: info: /etc/cont-init.d/udev.sh exited 0
s6-rc: info: service legacy-cont-init successfully started
s6-rc: info: service legacy-services: starting
services-up: info: copying legacy longrun supervisor (no readiness notification)
services-up: info: copying legacy longrun watchdog (no readiness notification)
s6-supervise watchdog: warning: unable to spawn ./run (waiting 60 seconds): Exec format error
s6-supervise supervisor: warning: unable to spawn ./run (waiting 60 seconds): Exec format error
s6-supervise watchdog: warning: unable to spawn ./run (waiting 60 seconds): Exec format error
s6-supervise supervisor: warning: unable to spawn ./run (waiting 60 seconds): Exec format error