I shake my head in disbelief. Cry. Then hold my children a little closer.

"Life changes in the instant," Joan Didion tells us in the opening lines of her latest book, "The Year of Magical Thinking." "You sit down to dinner and life as you know it ends."

I was actually cleaning up from dinner when I got the news; it was a little after 8 o'clock Wednesday evening. Leah called.

Michelle, our mutual friend, had called her asking that she let all of us — five friends from college — know: Michelle's son, Austin, had died Tuesday evening while playing volleyball with his longtime girlfriend, Katie. He had collapsed on the court, apparently from an enlarged heart. When Katie ran to his side, he told her, "Don't worry, babe. I'll be OK." And then he died.

That's when I shook my head. Austin? It can't be. A healthy, strong man of 26? He had had an emergency appendectomy in January but was fully recovered. He was back to laying carpet, and his only health concern had been the wear and tear on his knees from the kind of work he did, not his heart.

The tears came. Deep sobs really. And my mind ran to my own children. John, my oldest, is eight months older than Austin.

Then I remembered the first time I met Austin, at a college reunion held in my home 26 summers ago, when Michelle and I were new mothers together. We were living several states apart and were reunited with friends for a long weekend.

My son, John, was there, sitting quietly in his high chair, watching as we talked and laughed our way through dinner. Austin was there, too, a newborn, squirming his way through the evening.

Austin squirmed his way through most of his short life. A rambunctious, mischievous child. Charismatic. Gifted. Challenging.

Austin was full of enthusiasm for whatever he did. Skateboarding. Fly fishing. Horseshoes. Volleyball. Even exploring the Internet. His father told the story at a gathering last Sunday in celebration of Austin's life of how, at 14, Austin had called his mother over to the computer to show her the swirling galaxies he had found on a NASA Web site.

"I thought the FBI was gonna come to my house on that one," remembered Michelle wryly.

My memories of Austin are mostly of Rice Lake, in Ontario, Canada, where our families would gather for a biennial fishing trip. Austin loved to fish. Really fish. He was up most mornings at dawn with his sister, Meredith, or brother, Patrick, crisscrossing the placid lake in search of a morning catch.

Afterwards, he would stretch out his lanky body in an Adirondack chair, his chiseled, handsome face staring at the calm waters. There he would sit, cradling a big serving bowl filled with his favorite breakfast cereal, or, later on in the day, a Molson beer.

In the evening, after another round of fishing, we would spend the rest of the day playing cards and telling stories. Austin was known for weaving a tale, spinning a yarn, dazzling the younger children with his derring-do. "Austin stories," my kids called them. Tales of growing up in the fast lane, living life on the edge.

On Tuesday, in the middle of a volleyball game, that life came to an end. Suddenly, without warning.

You shake your head and cry. You hold your children a little closer, reminded again that life can change in an instant. You pick up the phone, and life as you know it ends.