Goku → Grandpa Gohan
Goku's grandfather died after being crushed by Goku in his Great Ape form. The statement in Chapter 1 that he was already dead, the explanation of the Great Ape in Chapter 21, and Goku's realization in Chapter 233 that he was responsible are combined as the same past death. This is not a record that Goku intentionally killed his grandfather.
SourceChapter 1 — Bulma and Goku (Japanese: ブルマと孫悟空)Full Color Goku Training Arc, Vol. 1 · Akira Toriyama / Shueisha
Additional sourceChapter 21 — The Full Moon (Japanese: 満月)Full Color Goku Training Arc, Vol. 2 · Akira Toriyama / Shueisha
Additional sourceChapter 233 — Can He Do It!? The Spirit Bomb!! (Japanese: だせるか!?元気玉!!)Full Color Saiyan Arc, Vol. 4 · Akira Toriyama / Shueisha