In the United States during a typical year, injuries are responsible for more than 147 thousand deaths, 2.6 million hospitalizations, and 36 million emergency department visits. Injuries are responsible for more deaths among children, adolescents, and young adults than all other causes of injury combined. An injury is defined as damage or harm caused to the structure or function of the body by an outside agent or force, which may be physical, chemical, or psychological (i.e. injured feelings). When thinking about injuries it is useful to distinguish intentional injuries (homicide, suicide) from unintentional injuries (most burns, falls, motor vehicle crashes, etc.) because of the great differences in the implications for preventing these tragedies.