Crashing applicaiton in docker

I run something like this to in order to start a container, which runs my server.

sudo docker run -v /mnt/dev:/mnt/dev -i IMAGENAME /bin/bash -c “COMMAND |& tee /mnt/dev/output”

However at some random point in time, the docker image exists with code 0

All output from my server is piped to /mnt/dev/output, but there’s nothing in there indicating what caused docker to exit.

So I’m guessing COMMAND (server) crashed …

Normally I’d go and check syslog to see if there was any information on the crash … but I’m unclear as to how to debug the above situation now that the container has stopped.