Find out about a 16-year-old recovering alcoholic; a mother who fights to stop the crowds of underage American drinkers who converge on Tijuana, Mexico; an undergrad who celebrated his 21st birthday with 24 shots of hard liquor and ended up dead; and a man who's made it his mission to educate teens about alcohol advertising. Their stories bring an up-close view of how alcohol bears a destructive influence on young lives. 48 Hours reports.