YOU SAID:

I just saw a man get killed to death

INTO JAPANESE

私はちょうど男が死に殺されるのを見た

BACK INTO ENGLISH

I just saw a man die to death

INTO JAPANESE

私は人が死ぬまで死んだのを見ただけです

BACK INTO ENGLISH

I just saw a person died till death

INTO JAPANESE

私はちょうど人が死ぬまで死んだのを見た

BACK INTO ENGLISH

I just saw a person died till death