
Police were alerted to the knife attack around 9.30 am in the western city of Essen and responded by deploying commandos to search the college.
The victim, a 45-year-old teacher, suffered serious wounds and underwent emergency surgery.
“We do not yet know what the motive was,” a police spokesman told AFP.
Officers confronted the suspect less than 3km from the college and “used firearms” after he drew a knife, police said.
The youth was also receiving hospital treatment for injuries.
According to the Bild daily, the suspect was a student at the college.
The BIB vocational college in Essen offers training in nutrition and domestic science as well as social and health care, according to its website.