This is a bit of old news, but here’s the details from the NYTimes.com
Day after day, night after night, Francisco Hernandez Jr. rode the subway. He had a MetroCard, $10 in his pocket and a book bag on his lap. As the human tide flowed and ebbed around him, he sat impassively, a gangly 13-year-old boy in glasses and a red hoodie, speaking to no one.
After getting in trouble in class in Bensonhurst, Brooklyn, and fearing another scolding at home, he had sought refuge in the subway system. He removed the battery from his cellphone. “I didn’t want anyone to scream at me,” he said.
All told, Francisco disappeared for 11 days last month — a stretch he spent entirely in subway stations and on trains, he says, hurtling through four boroughs. And somehow he went undetected, despite a round-the-clock search by his panicked parents, relatives and family friends, the police and the Mexican Consulate.
And here’s another good breakdown from the Digital Journal
The boy, whose developmental disabilities kept him from approaching anyone for help, have also led him to keep his experiences during the 11 days from his mother, Marsiela Garcia, who says he has not told her anything about his time in the subway system.
If you’re wondering what Asperger’s syndrome is check out this definition from wikipedia
Asperger syndrome is an autism spectrum disorder, and people with it therefore show significant difficulties in social interaction, along with restricted and repetitive patterns of behavior and interests.

I think I saw some posters up for him. He must have been so scared. I’m glad he’s back home.
[...] This post was mentioned on Twitter by Merryn Affleck, Peter Brown. Peter Brown said: Bensonhurst Student with Aspergers, 13, lost on subway system for … http://bit.ly/6n6NlY #aspergers #autism [...]
Excellent article, I am a big fan of your blog, keep on posting that great content, and I’ll be a regular visitor for a long time.