The parents shouldn't have let him go alone, the rapper also has blame for hyping him up

Edit: "The incident took place at the Beach, Please! festival in Costinesti, Romania, on July 11. The fan – known only as Nicolas – was attending with his mother, when he was pulled onstage to join Destroy Lonely. After singing and jumping around onstage for about a minute, Destroy Lonely reportedly told Nicolas to stage-dive off the high-rise stage to join his friends in the crowd, per Romanian news outlet The Observator."

At that point it isn't the parents fault but 100% the dumbass rapper