Produced by Judy Rybak
[This story originally aired on April 18. It was updated on Dec. 29]
(CBS News) PHOENIX, Ariz. - When Jamie Laiaddee disappeared in March 2010, none of her closest friends noticed for weeks. The truth is Jamie had been fading from their lives for nearly two years.
"After your friend stops making an effort you kind of stop too. But I never thought Jamie would have been the one to stop making an effort," said Sheila Dubs.
It was completely out of character for the sweet California girl they all met as freshmen at the University of Michigan.
Sheila Dubs, Gweneth Newman and Jennifer Langguth say they quickly formed a lasting bond with Jamie.
"She's a good friend; we were a support network for each other," Newman said. "It's kind of like we had this rock, we had this family of friends that we were so connected with. And I remember leaving Michigan, it was just so reassuring that you were just a phone call away from feeling like you belong somewhere again."
They call themselves the "516 Girls," referring to the address of a house they shared in Ann Arbor, their senior year. They were passionate supporters of Michigan's Big Ten football team.
"We were obsessed with U of M football," said Dubs.
No one was a greater booster than Jamie.
"I think just -- I always picture her in my mind on football Saturdays, you know charging out to the stadium," added Newman.
Sheila Dubs says that she and Jamie had a special connection. Both were from immigrant families and both were under heavy pressure to succeed.
"I think our fathers were kind of the same, they put a lot of pressure on us to do really well in school, but I think she just wanted to make it on her own," she said.
Vunnee and Jimmy Laiaddee came to the United States from Thailand in search of a better life. They admit they pushed Jamie to go to medical school.
"You think that because you were pushing her to go back to school, she might have pulled away a bit?" Moriarty asked Vunnee.
"Yeah, she said...she's a big girl," she replied.
After graduation, Jamie landed in Phoenix, Arizona. The big valley was booming... the perfect place to blend in and make her own way. She eventually found a high paying job selling medical supplies. While it consumed her time, she managed to maintain her now long-distance friendships.
"We emailed each other a lot. Even though we all ended up in different locations, I think we still look to each other for support. ...the weddings were the big thing that kind of kept us together," said Dubs.
Far away in Arizona, Jamie was lonely. She joined a local University of Michigan alumni club, where she found friends who shared her deep love of Michigan football.
Marlene Buffa was the group's president.
"She was enthusiastic, but still she was reserved and quiet," Buffa said of Jamie.
But when she caught the eye of a handsome, young, fellow Michigan fan, Jamie found romance.
Bryan Stewart says the attraction was immediate.
"She was hot -- I mean how else do you put it?" he told Moriarty. "She had a really good smile and really got enthusiastic about the football games and would jump up and cheer and would sing with the fight song."
They started dating in the fall of 2007. About a year later, Stewart moved in to the home that Jamie owned in the trendy Phoenix suburb of Chandler. She was the bread winner, making well over $100,000 a year. Stewart, a personal trainer, made much less.
Asked if she paid most of the bills, Stewart told Moriarty, "Most of the big ones, yeah. ...But it's not like I was dependent upon her."
"Did you love Jamie?" Moriarty asked.
"I still love Jamie. You know, I just want Jamie to be happy. It's hard because I don't know if Jamie knows what it takes to make her happy," Stewart replied.
In August 2009, Jamie suffered a crushing setback. When the economy took a big downturn, she lost the thing she valued most: her high-powered job.
"Her career had been going so well for so long. And I think this was a pretty major blow to her," said Dubs.
She searched for months in Arizona, Florida and New Jersey, but Jamie couldn't find another job. When the real estate crash hit Chandler, and her property value plunged, Stewart says she became despondent and even more withdrawn.
"You know, it was like when it rains, it pours...for Jamie, it was pouring..." said Stewart.
Bryan Stewart says all of it took a toll on their relationship, so he rented an apartment in Scottsdale and planned to break things off. And on the night of March 17, he said, he was going to tell Jamie he was moving out. Instead, he says, she surprised him.
"She came in -- asked me to take a week off from work. ...And she's, like...'we're gonna go to Denver. We're gonna get a house...I've got a job offer up there. ...It's time to go. I wanna go. I wanna get outta this state,'" Stewart said. "Basically I -- I told her no...I'm not leaving Arizona. I'm not gonna marry you."
Stewart admits Jamie was upset and that they argued. Still, he says, that when they went to bed, things had settled down. At the crack of dawn the next morning, he left for work.
"She was laying in bed. And I gave her a kiss, told her I loved her. And got in the truck and drove to work," explained Stewart.
But later that morning, Stewart emailed Marlene Buffa and told her a different story.
"And said, 'Jamie dumped me, she moved to--Colorado,'" Buffa told Moriarty.
"Did that surprise you at all?"
"No... I thought, 'Good for her.'"
"Did he seem upset?"
"Uh, a little bit. He was more angry that she left him alone."
"At any point did it even cross your mind that something could have happened to Jamie?"
"No, I knew she had means. If she wants to pick up and leave, good for her."
That day, and for weeks to come, no one realized that Jamie had disappeared.
"When is the last time you saw Jamie?" Moriarty asked Stewart.
"Physically saw her? 3:15 a.m. March 18, 2010," he replied.