Low Elo players who start feeding dont know how to stop

Every time I queue up for ranked, I'm low silver by the way, i have one or two (sometimes all 3) lanes that start feeding regardless of jungle pressure. The thing is they don't take the fact that they died into account the next time they fight. They dont farm and just keep feeding uncontrollably. I just had a game where I was 6/1 as Graves, I got top two assists and xp lead then he proceeded to die twice solo and ended the game 0/6. I got a double kill bot lane and then the enemy varus was somehow 6/4 the next time i went down there. How do I make people play safely and use the lead that I give them? I try to ward for my laners as much as possible, getting deep wards in the enemy jungle and whatnot laying pinks, but its been about 5 straight games that my team has just failed completely.