Katie Couric's Notebook: Taconic Tragedy

Last week, a woman named Diane Schuler got on the Taconic State Parkway in New York and headed in the wrong direction for nearly two miles. She collided with a truck and ultimately killed eight people, including her 2-year-old daughter, her three young nieces, three men in the other vehicle, and herself.

At first it was a mystery. Some suspected she became disoriented or perhaps had an aneurism. What other explanation could there be, given the precious cargo she had on board?

Well, today, prosecutors report that marijuana and twice the legal limit of alcohol were found in her blood stream.

According to Mothers Against Drunk Driving, a person is killed by a drunk driver every 45 minutes. In this case, eight lives were lost in a matter seconds, making this senseless tragedy even more difficult to understand.

That's a page from my notebook.

I'm Katie Couric, CBS News.