One middle school student was taken to the hospital Tuesday after two incidents where children held their breath until they passed out, according to a letter their prinicipal sent home to families. Lynn Irby Hill, head of South Orange Middle School, urged families to talk to their about the dangers of the blackout challenge, which children have learned about on social media. One student needed help from the school nursing staff, she wrote, and a second student had difficulty resuming breathing and was taken by ambulance to a hospital, accompanied by assistant principal Jim Waldron. School offi…