Third strike touching ground before before being caght by catcher

[coachnatte]

Bear with me one more time on this issue.The bases are loaded with 2 outs. The BR swings and misses on the third strike and the ball is not caught by the catcher. The ball deflects toward the third baseman.The runner at third hesitates at first as the batter runs toward first. The third baseman seeing he has no chance to throw the BR out sees the runner at third break for home. He makes his throw to home in a play on this runner. My question is: Is this a force play at home or does the runner going to home need to be tagged out?