▁finally ▁ret iring ▁in ▁ 1 9 5 3 . ▁ ▁Gro ff ▁died ▁of ▁a ▁heart ▁attack ▁in ▁O ce ans ide , ▁California ▁on ▁October ▁ 2 , ▁ 1 9 9 0 ▁at ▁the ▁age ▁of ▁ 1 0 0 . ▁ ▁He ▁is ▁inter red ▁at ▁R ivers ide ▁National ▁C emetery . ▁ ▁References ▁▁ ▁This ▁article ▁incorpor ates ▁public ▁domain ▁material ▁from ▁documents ▁of ▁the ▁United ▁States ▁Marine ▁Corps : ▁ ▁U . S . ▁Marine ▁Corps ▁M uster ▁Roll s , ▁ 1 8 9 3 – 1 9 5 8 ; ▁( National ▁Archives ▁Micro film ▁Public ation ▁T 9 7 7 , ▁ 4 6 0 ▁roll s ); ▁Records ▁of ▁the ▁U . S . ▁Marine ▁Corps , ▁Record ▁Group ▁ 1 2 7 ; ▁National ▁Archives , ▁Washington , ▁D . C .; ▁and ▁John ▁Gro ff ' s ▁U . S . ▁Marine ▁Corps ▁Service ▁Record ▁ ▁Wil k erson , ▁John . ▁" About ▁the ▁' H on or ▁Men ' ." ▁The ▁Le ather ne ck ▁ 2 6 . 5 ▁( 1 9 4 3 ): ▁ 4 9 . ▁Print . ▁ ▁External ▁links ▁▁▁ ▁https :// www . ny times . com / 1 9 9 0 / 1 0 / 0 6 / ob itu aries / br ig - gen - j ohn - gro ff - d ies - at - 1 0 0 - a - marine - h ero - of