Radiation overdose – Melting flesh
Life is draining from you – Toxic death 

Rotting from the inside out – Flesh turns grey
Inhaling radiation fumes – Lungs decay 

Sickness from the radiation makes you lose your mind
Hair falls out, internal bleeding [bad word] makes you blind Radiation burns your flesh – Soon you'll die
Poisoned clouds of toxic rain in the sky 

Start to [bad word] [bad word]  still alive
Rigor Mortis freezes you, now you die