One major event in Darry's life happens prior to the opening of the story when his parents are killed in a car crash. Ponyboy tells the reader that Darry was very close to them, particularly to his father, and that after his death his life changed dramatically. Although he didn't show a great deal of emotion, it is clear that he immediately felt the weight of his responsibility to keep the family together. So he holds down two jobs and fights to make sure the two younger boys don't get sent to a group home.
Another major event in the story was when Darry hits Ponyboy. He is frustrated and Pony thinks he is just being mean but he loses his cool and slaps him. This of course is the night that Pony runs away and finds Johnny and they end up getting attacked and Johnny kills Bob.
One more major event could be the day that he and Ponyboy are reunited at the hospital. Darry has been worried sick and no one would tell him where Johnny and Pony were hiding out but he is overcome with relief when he sees that Ponyboy is going to be ok.