Update

A day or two after I posted US Marine Casualty Cards I received a follow up email.  They had seen my post and sent me the following email:

In response to your post about the code on the casualty card regarding the nature of Sergeant Thomas' death, we can tell you that what you see is a code for inputting into a larger (long since gone) database.  Because the original database that used this code is gone, we have no know way of knowing what the code stood for.  However, we have attempted to locate more information by accessing the muster roll for Company A, 1st Battalion, 24th Marines for March 1945.  The muster roll unfortunately only stated that he was wounded and later died of those wounds.

Despite this lack of information, there is still an option left open to you.  The National Archives located in St Louis, Missouri, holds the service of Marines for this time period.  I would suggest that you contact them and obtain a copy of the military service record for Sergeant Thomas.  More information about getting copies can be found on their website at http://www.archives.gov/veterans/military-service-records/ 

We hope this is helpful and hope your search for answers comes to fruition.  If we can be of further assistance, please do not hesitate to contact us.

 They also sent me a pdf attachment of two sheets of the muster roll pertaining to Fred.

The next step in finding out more will be to contact The National Archives in St. Louis and obtaining a copy of his service record.

I am thoroughly impressed with the service they provided me and I hope that any of you who have US Marines in your family will use this wonderful resource to gain valuable information about your ancestors!