Sure thing. It is just a supposition IF Madara was able to do it. Thinking in Shodaime, and Nidaime too... How did they died? I mean, the human 1st and 2nd hokage, not the zombies... I´ve never read about it... But that´s not the thread...
I also assumed that 1st died of injuries sustained from after the fight with Madara. But whether thats true or not, I do believe that the 1st died young though. Hopefully, the details of that fight will be covered in a Madara flashback.
so , madara is not that strong anymore right now?
Kakuzu said he fought the 1st. Not killed him.