One devastating morning five years ago, the life of California advertising executive Jack Grandcolas changed — forever.

That morning, Sept. 11, 2001, 38-year-old Lauren Grandcolas — Jack's wife of 10 years who was three months pregnant with their first child — boarded an earlier flight than scheduled 2,500 miles away, from Newark, N.J., to San Francisco.

Her plane, United Airlines Flight 93, was to become the fourth and last airliner hijacked that day.

Instead of hitting its intended target, believed to be either the White House or the U.S. Capitol, Flight 93 went down in a field in Shanksville, Pa.

In that moment, Jack Grandcolas transitioned from husband to survivor.

"It's a completely different life," said Grandcolas, 43, of San Rafael, Calif. "You go from being a husband and potential father to being a widower, having a home that's empty. Half of you is gone."

He and Lauren had moved into a house suited for starting a family. She'd had other pregnancies that hadn't gone full-term, he said, so they were waiting until after she returned from her grandmother's funeral in New Jersey to tell relatives the good news they'd only found out a week or so before she'd left for the East Coast.

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So many plans and dreams, like those of so many victims and families, died in an instant on Sept. 11.

Grandcolas was in shock, barely managing the basics: getting out of bed in the morning, bathing, eating what little he could.

"You start off with just the surreal sadness of it all," he said. "There are so many stages of grieving. There's never closure. There's chapters of closure. Those chapters come daily, weekly, monthly. But the final closure won't come 'til the day I die."

His life became unrecognizable to him. He attended his wife's funeral services in California and Houston, her hometown, and other Sept. 11 memorials. The White House extended an invitation to him and the rest of the victims' families, and he went. Eventually, he gathered the strength to sort through Lauren's clothes and other personal things, the evidence of her life. He read a mountain of sympathy notes and answered as many as he could. He did media interviews when he felt it was necessary.

"You kind of live in a zombie state," Grandcolas said. "It's as if someone rips open your chest, reaches in and grabs your heart, shoves it back in your chest and says, 'OK, walk on.' You've been mortally wounded, but you're not dead. It's an odd feeling. I wouldn't wish it on anyone."

Shock was replaced by longing.

Longing to have Lauren — his best friend and love, the woman he'd met in college in 1985 and spent 15 years with — back again.

Longing for things to be different.

Finally, he realized that depression had crept up on him. A therapist later diagnosed him.

"I'd lost 30 pounds. I thought I had cancer," he said. "My grief counselor said, 'No, you're just depressed.' … It probably set in immediately, but it takes time to do its damage."

Once he knew what he was dealing with, he was able to begin to heal, he said. He started exercising and trying to seek those "brighter moments" in the day to carry him through.

"People really do come to your rescue," he said. "It's amazing. You live on in your loved one's spirit. I remember hearing Lauren say, They may have gotten me, but they're not going to take you, too."

He didn't go back to work full time until January or February, though he began easing into it in November and December.

Slowly, Grandcolas was able to get involved in positive projects born out of the tragedy.

He and others in Lauren's family set up an organization in her name, The Lauren Catuzzi Grandcolas Foundation, and held fundraisers, with proceeds going to scholarships for young women and to support a neonatal care unit at a Houston hospital.

He and the rest of her family raised $50,000 to establish a birthing room at Marin General Hospital, where she likely would have had their baby, "to add some silver lining to a great cloud," he said.

"Because she cared so much about babies and loved them so much and was very compassionate to mothers, it just seemed like the right thing to do — just to have something in her name helping mothers and babies every day, year in and year out," Grandcolas said.

He visits Lauren's birthing room regularly.

"It's the unexpected return on that donation that is really kind of bittersweet," he said. "It brings a lot of inspiration."

Grandcolas knew that one of the first things Lauren would have wanted him to do was finish and publish the book that she'd recently begun, inspired by her childhood days earning badges as a Girl Scout. He did just that, with the help of her two sisters.

"You Can Do It: The Merit Badge Handbook for Grown-Up Girls" — a how-to guidebook motivating women to do everything from skydiving to cooking a good meal — was published in May 2005.

"She was a very strong woman," he said. "It was very important for her to show other women that anything a man can do, a woman can do."

When it came time for Flight 93's story to be told, Grandcolas, along with the other family members, consulted with director Paul Greengrass on his film "United 93," which opened in April. Grandcolas bristles at the suggestion that the movie was released too soon, "when every single family member agreed it wasn't."

"If it's not too soon for me, then how can it be too soon for you?" Grandcolas questioned. "We're relieved the story is out there … I thought it was provocative, powerful, honorable.

"Obviously it is a difficult thing to relive the ending of your loved one's life, but I thought it also had a hint of inspiration," he said.

Grandcolas recently attended a U2 concert with some friends, one of whom knows lead singer Bono. The show had particular significance because Lauren and Jack went to a U2 concert in 1985. It was their first date.

"I still have the ticket stub," Grandcolas said.

Now, he was again seeing the band play, this time without Lauren. His friend arranged for Bono to dedicate the song "One Tree Hill" to her.

Bono told the audience, "This is for beautiful Lauren."

"That tribute was magical. I just had to bury my head in my hands," Grandcolas said. "She was beaming down on us. It was just one of the happier moments of closure, one of those things where you say, 'Now I can move on one more step.'"

Grandcolas eventually moved out of the house he shared with Lauren, though he stayed in San Rafael. Five years after his life suddenly changed, he is trying to look ahead rather than dwelling on the past.

He's working to help raise money for a permanent United 93 memorial in Shanksville. He plans to stop talking to reporters after this year and concentrate on taking better care of himself.

And, he's allowed himself to think about the possibility that someday he might marry again and have the children he's always wanted.

"Reliving it every year like we do, it's not healthy," he said. "I'm going to do what Lauren would want me to do, maybe meet someone else and have a family. It's possible, and I’m hopeful. It's not like going to the grocery store and replacing an item you've run out of. It's a process. It's kind of frightening, to be honest."

Though he agrees that no one will ever fully know what happened aboard United 93, he believes that along with the rest of the passengers, his "petite, beautiful, dynamic" wife — a marketing coordinator, a trained EMT and the type who would take charge and inspire others to do the same — did successfully thwart a fourth grand-scale attack on Sept. 11, 2001.

"It's another silver lining to that gray day," Grandcolas said. "These people rose up and turned the tables on the terrorists."

One of the things for which Grandcolas is most grateful is Lauren's last message to him, forever recorded on their answering machine.

The phone's ringer had been turned off, as usual, he said. Otherwise, he would have picked up and learned that hijackers had taken control of her plane, and he would have been left with haunting memories of how Lauren and her fellow passengers spent those final moments.

Instead, he has the recorded goodbye of a calm and loving wife that he can keep with him, always.

"Jack, pick up, Sweetie," Lauren said on the voicemail. "I'm OK. I just wanted to tell you I love you. There's a little problem on the plane. I'm totally fine for now. I … I'll … I love you more than anything. Just know that. Please tell my family I love them too."

"It's a gift," he said. "She was a bright light in the world who is now a star in the sky."