Alcohol use increases your risk for many causes of death, especially those that we ordinarily think of as "accidental": Motor Vehicle Accident, Hit by Car, Drowning, Alcohol Poisoning, Fires and Burns. (Of those, this program only uses alcohol as a risk factor for motor vehicle accidents.)
Alcohol use is also a risk factor for some non-accidental illnesses: Cirrhosis of the liver, Mouth cancer, Throat cancer.
The risk for the accidental causes of death returns to normal almost immediately after quitting alcohol. The risk for non-accidental illnesses takes longer to normalize.
You can get more information about alcohol from the National Institute of Alcoholism and Alcohol abuse or from AA.