Thank you for posting. I apologize for the late reply.
It's likely the "black screen power off indication" is a Mac OS X kernel panic.
Please refer to this knowledge base article from the Apple Support site to see if this is what is happening on your Mac:
This article gives a very detailed list of troubleshooting steps, should that be what you are seeing.
I would be concerned about the possibility of corruption to the files that you had open when these crashes happened. For the FileMaker files, you should run Recovery. If damage is found, it would be advisable that you revert to known-good backups of your files.
Please let me know if you have additional details since your post that may be helpful in identifying what happened.