Three students were injured in a stabbing incident at Carrick High School in Pittsburgh on Wednesday morning, with one in critical condition. The incident occurred around 8:30 a.m. during a hallway altercation, which was not random according to authorities. The victims, boys aged 15 to 18, included two who sustained stab wounds to the abdomen and a third with a minor laceration, treated at the scene or transported to the hospital. A student has been taken into custody and is being questioned at Pittsburgh Police headquarters. The school is on lockdown as police investigate, gathering video footage and interviewing witnesses. The cause of the altercation and security measures at the school remain under investigation.