Heidi & Spencer in Colorado for Stepbrother's Memorial
03/04/2008 AT 02:10 PM EST
O'Hara, a veteran of combat missions in Iraq and Afghanistan, died Thursday at the Steamboat Grand Resort Hotel after slipping off a sloped roof while attempting to remove snow.
"Losing my brother, at an early age, is such a tragedy," The Hills star, 21, said in a statement. "I just loved him more than anything," Montag's statement continued. "He was just so patriotic. He really wanted to go to Iraq and help and do all that he could for his country. He felt like it was his duty. I'll really miss him."
–Mary Margaret and Brian Orloff