Locating People/Verifying a Death

I've been trying to track down one of my DIs in Marine boot camp. Went through basic in 1968 at MCRD San Diego. I recently called a former Drill Instructor, living in Texas and retired from USMC, who worked with and knew the DI in question. He told me that he heard the DI had been killed(he thought in a car accident), after his second tour in Vietnam.

This would have been between 1969-1973. I checked the National Cemetery Administration website. Punched in his name, etc. and no record of him buried in a Military cemetery. I also checked the Social Security Death Index, and again no record of the DI in question. This leads me to believe that he might be still alive!

My question to you is what website sources can I use to verify if an American has indeed died? Also, do you have any tips on locating this person if he is indeed still living? I have his first and last names(not middle name, but initial), his USMC military service number, his approximate age, where he used to live before he entered the service in 1959, and of course his rank, time and place of his whereabouts when he was my DI.

I'm trying to do this search for free, and without having to mail the Military Records in St.Louis, and wait weeks and even months.

Any tips and information you can give me would be very much appreciated. I'm not the only one looking for this person; many friends he had as a teenager in Los Angeles have been trying to hunt him down for years. Thank you.

Art Granville
Hemet, CA";