MADD’s mission to prevent underage drinking and drug use is deeply personal to me.

My daughter’s life ended when a 17-year-old made the deadly decision to drink alcohol and smoke marijuana – then get behind the wheel of her car. My daughter, Helen Marie, had just turned 16 when she was struck while rollerblading on a bike path just a few blocks from home. She died instantly. My family’s life changed forever.

Young people who drink are a danger to themselves, their friends, and others. Teen alcohol use kills about 4,300 people each year. And teens don’t have to drive for drinking to turn deadly; in fact, two out of three of these deaths do not involve a vehicle.

Almost half of all 10th graders drink alcohol – a startling statistic. But we have reason to be hopeful. Parents are the No. 1 influence on their child’s decisions about drinking, and communication with teens about alcohol can reduce drinking behaviors by 30 percent.

As a parent, you have the power to make a difference.

That’s why MADD has designated March 1 through May 31 as PowerTalk21®, which I kicked off this month in Miami. Part of our Power of Parents® program, PowerTalk21 gets parents talking to their teens about the consequences of underage drinking and drug use. This is a crucial time to start having conversations or to renew them if you’ve already started. The next three months include milestone events like spring break, prom and graduation – occasions that can increase the presence of alcohol.

Don’t know how to start or what to do once you have? Parents can access extensive resources, including a downloadable parent handbook at madd.org/powerofparents. These resources are also available at your local MADD office. And over the next three months, MADD will offer free, 25-minute Power of Parents parent workshops across the U.S.

This year, MADD is expanding its reach by encouraging parents to use the tools included in Power of Parents to not only talk to their kids about alcohol, but other drugs as well, including marijuana, which is the leading cause of substance abuse in the U.S. behind alcohol.

I know firsthand the immediate and life-altering consequences of teen alcohol and drug use. There are also other reasons for teens to avoid these behaviors, and why the national drinking age remains 21. A teen’s brain is still developing, making it more easily damaged by alcohol and other drugs – including marijuana.

Teens who don’t drink alcohol before age 21 are 85 percent less likely to become a drunk driver later in life and are 80 percent less likely to abuse alcohol or become alcohol dependent.

And teens who start drinking young are seven times more likely to be involved in an alcohol-related crash. These crashes destroy lives and affect entire communities.

Just before Helen Marie left to go rollerblading on June 1, 2000, she told me our local photo studio had called. She’d recently had her portraits made, and the images were back.

We couldn’t have known they’d be the last ones ever taken of her, or that we’d be picking them out without her. Or that the beautiful young girl smiling back in them would never grow older, all because of one 17-year-old’s decision.

If you haven’t talked to your teen about underage drinking and drug use, please start now. If you have, please, Keep Talking. It Matters Now More Than Ever.