Death among children and adolescents. Accidents (unintentional injuries) are, by far, the leading cause of death among children and teens. There are almost twice as many deaths in the first year of life as there are in the next 13 years combined. Then, the death rate rises rapidly after puberty because of the large number of accidents, homicides, and suicides in the 15 to 24 age group. These three causes of death in teens should all be preventable.