(CNN) -- The biological mother of a missing 7-year-old Oregon boy has written an open letter to her son saying, "I am sorry that I was not there to protect you." 

"I am so soooooo sorry that this has happened," Desiree Young wrote to Kyron Horman in a letter that was released Monday to NBC News. 

"I will never be able to forgive myself for being so many hours away when you needed me the most. I pray that you come back to me because I am afraid that I can't live without you." 

The letter comes more than two weeks after the boy disappeared on June 4. 

The boy's stepmother, Terri Horman, said she last saw Kyron walking down the hallway towards his classroom at Skyline Elementary School, police said. Cell phone records indicate she may not have been at the school at that time, according to a report in People Magazine. Authorities refused to comment on the report. 

In the emotional letter, Young speaks directly to her young son. "When you come home I will show you all of [the] things that everyone did for you, just to find you," she wrote. 

"There are literally hundreds of thousands of people that don't know you and yet they pray for you every night. They know how much I miss you and need you and they just want to bring you home to me. There are so many wonderful people working on this case and they are going to find you soon. 
How old was her son?
 The biological mother of a missing 7-year-old Oregon boy has written an open letter to her son saying, "I am sorry that I was not there to protect you.