If possible, consider using the formative experience as the basis for the beginning of your essay. Introduce the impact that event has made on your life as related to your family's interactions, your academic activities, and your plans for your future.
In the body of your essay, provide more information about this critical episode in your life. Include in that description quotes taken from your interview with someone who shared the event with you and who understands how it has changed your life. Other paragraphs in your essay can more fully present information about how your family has supported you in continuing to grow as a result of the experience, how it has shaped your class selections and extra-curricular activities, and how it has impacted your planning for post-high school training.