Most of Memorial Day passed as a relaxing holiday for my family. We watched sports on TV and munched on leftover ribs from Sunday's barbecue.

In the early afternoon my 18-year-old son and I went out to rent a tux and order a corsage for his upcoming prom. A little while after we returned home, he rushed in from our frontyard.

"Did you hear that?" he asked. "It sounded like a huge explosion."

Then the sirens wailed, and a helicopter droned overhead. My son's girlfriend called. "Oh no," I heard him say. "Oh no."

Five people dead in a crash on Jamboree Road, just a short distance from our home, on a stretch of pavement we've passed countless times over the years. Please don't let it be kids, please don't let it be kids, I silently intoned.

We all know now that it was. Five teenagers from Irvine driving toward Coast Highway for a late afternoon at the beach on a lovely spring day were here one instant, gone the next. The horror of it seemed inexplicable, unimaginable.

Except that it's not. We take calculated risks every day, allowing young people whose brains aren't even finished maturing to operate fast-moving, heavy machinery powered by combustible engines. Accidents are as inevitable as they are tragic.

Here are some of the grim statistics and other findings, culled from reports by government agencies and private institutes:

•Traffic accidents are the leading cause of death among teens. Teenagers are three times more likely to be involved in a fatal crash than all other age groups. Sixteen-year-olds have the highest crash rate of any age.

•About 3,000 teenagers are killed in auto accidents in the United States every year. Most fatalities occur when a teen is at the wheel. The deadliest time of year is from Memorial Day to Labor Day.

•The teenage fatality rate is 3.6 times higher when there are passengers in the car; the relative risk increases with each additional passenger.

•The crash rate for teens is three times higher after 9 p.m.

•The major contributing factors behind fatalities in which teenage drivers are involved are inexperience and immaturity leading to bad decisions and risk-taking behavior; alcohol and drugs; a failure to wear seat belts; distractions such as cell phones, texting and other kids; drowsiness; and nighttime driving.

What can we parents do to ensure that our kids are driving safely and responsibly?

The Centers for Disease Control and Prevention's "Parents are the Key" campaign offers these suggestions:

•Practice driving with your teenager frequently.

•Insist that your kids always wear seat belts. No seat belt, no keys.

•Restrict your teen's driving at night and with multiple passengers.

•Talk to your kids often about the rules of the road and potential hazards.

•Enter and enforce a "driving agreement" with your teen.