Alcohol is not a drug, it is a fuel.
Once consumer, it suffocates the brain of oxygen and nutrition leading to drunkenness, dead and damaged brain cells and an imbalance of neurotransmitters.
Heroin, once consumed, it merely binds to opiate receptors in the brain, therefore it doesn't harm the brain or any organs in the body.
90%+ deaths from "heroin" are the result of it's illegal status. People who want heroin buy stuff from off the street (the only place they can get it) and most of contains a lot of impurities and dangerous chemicals which results in deaths.
And marijuana is safer than sugar or coffee.
The 'War on Drugs' thrives and survives on ignorance.