How to identify the cause of a restart on MacBook Air via Console app in OS X Yosemite Recently my MacBook Air restarted in the middle of the night and cost me some data.

I understand there is a support page that tells me the possible causes, but they don't include a way to find the cause. 

Is there a way I can identify the cause of a reboot via the Console app?
Using the console


Open Console app (by default located in Macintosh HD⁩ ▸ ⁨Applications⁩ ▸ ⁨Utilities⁩)
Select the system.log file in the left pane
Conduct a search for Shutdown Cause
View the filtered output


See Yosemite example below:



NOTE: For more context, you may want to search for Shutdown only to see some of the other log entries and not just the Shutdown cause.