Looks like the site has been revised extensively and the revision is still in progress. The "old" action code list can be seen here, scroll down to the Action Codes:
https://web.archive.org/web/20180315...elp.htm#USNabb
KCRGCDF could mean something like Killed, Crash, Ground Collision, Destroyed (by) Fire.
KCRGCF could mean something like Killed, Crash, Ground Collision, Fire