In The Outsiders, when and how did Ponyboy’s parents die?

Ponyboy Curtis and his brothers Sodapop and Darrel (nicknamed Darry) lost their parents approximately eight months before the start of the Novel The Outsiders by S.E. Hinton. When this happens, Darry, who is the eldest of the three brothers, takes over as the family's protector and guardian. At the beginning of Ponyboy's narration, Darry is 20 years old. This means that if their parents had died a few years ago, he would have been a minor, underage, and therefore unable to keep his family together. Likely, three underage orphaned boys would be put into the foster care system. However, because Darry was over the age of majority at the time of the mother and father's deaths, he becomes the legal guardian of his 14 year old brother Ponyboy and his 16 year old brother Sodapop. 

The Curtis parents died in a car crash. When the book begins, the emotional wounds of their parents dying and them being orphaned are still fresh and hurting. They still feel very strongly about this traumatic event in their lives, which indicates that it wasn't very long ago. The parents' deaths are significant because it forces the Curtis boys to rely even more on each other and on their Greaser friends. It changes Darry the most. Before the car crash, he was popular in school and had a lot of potential. When their parents died, he had to give up his dream of going to college in order to take jobs to take care of his two younger brothers.