The causes of homelessness are complex and poorly understood. This paper describes the homeless population in Santa Clara County, California in terms of Adverse Childhood Events, Traumatic Brain Injuries (TBIs), and family breakdown. Respondents reported severely traumatic childhoods; 78.7% grew up in a household with a person with drug or alcohol dependence and 64.6% endured psychological abuse as a child. Seventy-six percent of subjects recalled at least one TBI, 58.4% with loss of consciousness. Nineteen percent were in foster care as children and 40.2% reported having someone other than a parent as a primary caregiver. Fifty-three percent felt they had moved too much as children, and 37.5% had experienced homelessness as children. Santa Clara County has both the highest median income and the highest rate of unsheltered homelessness in the nation. Leaders and community members should work together to improve the lives of the homeless and to prevent another generation of homeless people.