Before he took his own life last Friday, Michael Blosil -- Marie Osmond's 18-year-old son -- gave few warning signs to friends.
"He was always smiling," a grieving friend tells UsMagazine.com. As recently as two days before he jumped off the seventh floor of his L.A. apartment building, the young man seemed "really happy, always making jokes," the friend says.
The pal -- who prefers to remain anonymous -- was a classmate at L.A.'s Fashion Insitute of Design and Merchandising, where Blosil enrolled last October.
"We hung out every single day, a group of us," the friend says. "We would jump in the car with our pajamas on and go to Carl's Jr. We would go shopping."
And Blosil relished the atmosphere at FIDM, too. "He would tell me how much he loved his classes, that the teachers were cool and the girls were pretty," the pal recalls.
Yet he reportedly left a despondent note for a female friend and neighbor; discovered minutes before his suicide, the missive told of how alone and friendless Blosil felt.
"That was a shock," the pal says of the note's sentiments. "It wasn't like he was a loner type." If anything, Blosil -- who was "very close to his mom" -- was the one to cheer up friends who were in the dumps, the friend says.
"If you were sad, he would be the one to make you feel better. He would find a way to make you laugh. He was there if you needed anything." Prior to FIDM, Blosil struggled with depression, and entered rehab in 2007. At the time, his mom Marie applauded his "courage in facing his issues. As his mother, I couldn't be more proud of him."
Although in seclusion as she mourns, Osmond, 50, posted the following statement on her Twitter and Facebook accounts (her rep had released the same over the weekend):"My family and I are devastated and in deep shock by the tragic loss of our dear Michael and ask that everyone respect our privacy during this difficult time."
Read more about Michael Blosil's tragic, shocking death in the new issue of Us Weekly, on newsstands now.