Leavers or afk's in ranked

There should be a system that is implemented that either prevents lp loss with any games that has anybody that has been afk or stationary for more than 5 minutes. I have lost several games this season just because it was constant 3v5. The domino effect is terrible. One person leaves, and then another leaves. Pretty soon it is just you and some random person, just sitting there for about 15 minutes wasting time doing nothing.