PORTLAND, OR- OCTOBER 18:   Shannon, 24, has been on the streets since she was 17.  She lost her legs in an accident attempting to jump aboard a train.  She had the use of a wheelchair while her prosthetic legs were being repaired.  She has been beaten and raped because she does not have the ability to "run away" when she encounters danger.      Portland, Oregon has the highest population per capita of homeless youth in the United States.  An estimated 2500 youth in Portland lack permanent housing and live on the streets, in shelters or "squats." According to studies, over 90 percent of Portland's street kids are victims of sexual and physical abuse. The epidemic spread of "meth", and some of the cheapest heroin in the nation fuel a high rate of drug addiction in this demographic.  Infection of incurable diseases such as Hepatitis C and HIV is also rampant among homeless youth.  The average life expectancy for a homeless youth living on the streets is 26 years of age.  (Photo by Jonathan Ferrey/Getty Images)