Energy drinks such as the Monster Energy Drinks are okay to drink in moderation but if you drink too many Energy Drinks then yes it could likely kill you.
When drinking energy drinks they speed up your heart rate to increase your energy levels which is not healthy if your heart gets sped up too much.
I drink one Energy Drink per day which is enough and I used to drink 2 energy drinks per day and I noticed my heart was beating too fast and the doctor said it was caused by drinking the energy drinks.
After I stopped drinking too many energy drinks and only drank one energy drink per day my heart beat went back to normal.
So yes energy drinks can be bad and kill you if they cause a heart attack which they can do if you drink too many energy drinks.