Final answer:
The death of Edgar Allan Poe's mother when he was three is considered the first tragic event of his life, significantly impacting his later works and themes.
Step-by-step explanation:
The first tragic event in Edgar Allan Poe's life was the death of his mother when he was just three years old. This loss is hypothesized by some, such as Marie Bonaparte in The Life and Works of Edgar Allan Poe (1933), to have had a profound psychological impact on Poe, influencing his literature. In his works, like "The Fall of the House of Usher", themes of death and loss are prevalent, reflecting Poe's ongoing preoccupation with the death of his mother and his experiences with tragedy thereafter.