On a rainy October evening 39 years ago, my older brother Greg embarked on a typical Saturday night’s activities. At 17, he managed to be both active in our church and a social live wire: He was the popular president of his high school senior class and a party guy. That night, perhaps because our parents were away and my grandmother was looking after us, Greg decided to cut loose. He and a good buddy began by going to a dance at a nearby girl’s school. There, Greg got a purple stamp on the back of his right hand: Convent of the Sacred Heart, it said. Later, he and his friend went back to his friend’s house and started drinking margaritas. A lot of margaritas. His friend’s parents were home, but they were — like I am now — middle-aged and tired. They had gone to bed.

What they did by going to bed is, to my mind, the same thing that Maryland Attorney General and gubernatorial candidate Doug Gansler did in June when he walked through a Delaware beach house party where his newly graduated son was serving as DJ for his high school classmates. The vivid photo published last week of Gansler surrounded by a crowd of high school partyers — complete with a girl in skimpy clothes and two bare-chested boys dancing on a table — more or less says it all.

There are lots of red paper cups in evidence, and Gansler says that he suspected that underage kids were drinking, but he did nothing. Admittedly, Maryland’s top law enforcement official does not have jurisdiction in Delaware. But that did not absolve him of a moral duty to protect the kids under that roof and, at a minimum, stop the drinking — on threat of reporting it to local police.

This would perhaps have made him, at least temporarily, an enemy in the eyes of his son. But it would have made him my hero.

We adults are — many of us, anyway — complicit in a look-the-other-way culture around underage drinking that makes me both angry and sad and leads to the endless waste of young lives. The Centers for Disease Control and Prevention reports that alcohol kills 4,700 young people every year. They fall from balconies, they lose consciousness in pools of their own vomit, they stagger into oncoming vehicles, they drown. Many become victims of homicide or suicide. Tens of thousands others are injured and maimed. Add all those killed by drunken teen drivers, and there is more than enough grief to go around. And yet, we fail to enact even such simple measures as laws holding adults accountable for hosting underage-drinking parties. Of Virginia, Delaware, Maryland and the District, only Maryland has such a law on the books.

I admit it’s tough to draw lines with teenagers. My own sons are 13 and 15, and I struggle daily to be a wise parent, to know when to give a little and when to stand firm. But I don’t buy the “kids will be kids” argument that advises adults to wink and nod at underage drinking because it’s going to happen regardless. It’s not true that the attitudes of adults, and their seriousness about laws and rules, have no influence on teenagers’ drinking habits.

Consider the findings of the College Alcohol Study by authors at the Harvard School of Public Health who spent eight years studying more than 50,000 students at 120 colleges. They concluded that students drink more on campuses that have a strong drinking culture, few alcohol-control policies and weak enforcement. They found that at some colleges very few students engaged in binge drinking, while at others, four out of five students reported bingeing. Don’t tell me that college policies and cultures — in other words, the tone set by those in authority on campus — have nothing to do with these disparities.

The University of Florida is a case in point. Once known as a top “party” school, the campus’s binge-drinking rate dropped from 57 to 38 percent in the four years after administrators adopted tough measures that included mandating alcohol education for freshmen and banning alcohol advertising at concerts and sports events. At the University of Virginia, there was a 33 percent decrease in binge drinking, an 81 percent decline in drinking and driving, and a 76 percent drop in alcohol-related injuries over the decade that ended in 2010. In 1999, administrators, working with students, launched a high-profile marketing campaign that features ads – often in dormitory bathroom stalls — such as one proclaiming: “86% of UVA students usually intervene to stop friends from drinking and driving.”

I wish a friend had intervened to stop my brother and his buddy, who decided around 2 a.m. on that October night that it would be a good idea to go out for something to eat. It was the friend who was at the wheel of his mother’s green Hornet station wagon when it skidded at 40 miles an hour, with Greg in the passenger seat. It ended up wrapped around a lamppost, with Greg jammed between the seat and the door. The passenger side of the car was so smashed that the first person on the scene didn’t realize someone was in the passenger seat. The only good news in this story is that Greg’s friend survived the crash without serious injuries.

It was just a few years ago that I first looked at the autopsy report, which is how I know that Greg had that purple stamp from the Convent of the Sacred Heart on the back of his hand. My beautiful brother also had a fractured skull and pelvis, a ruptured bladder and a right cheek lacerated with glass fragments. There was vomit in his lungs; he had inhaled it at the very end. His blood alcohol level was .28 percent — 3.5 times the current legal limit for driving.

To his credit, Doug Gansler has publicly acknowledged that he made an error in judgment in June. If he survives the controversy and is elected governor, my sincere hope is that he will right that wrong by making it a top priority of his administration to curb underage drinking in Maryland.

The writer is a fellow at the New America Foundation and a member of Arlington’s Reduce or Eliminate Alcohol and Drug use in Youth (READY) Coalition.