In Tacoma, Washington, four students, a security guard and the suspect were hospitalised, with four critical injuries and two non-critical, officials said.
The school went into lockdown at 1:38pm, students were dismissed at 2:45pm, and one person was apprehended and placed in police custody.
Classes and after-school activities were cancelled for Friday, with counselling support planned when school reopens Monday, as police investigate reports the violence began with a dispute over a vape pen.
As vapes fuel school fights, is de-escalation training more vital than traditional security for preventing the next tragedy?
A vape pen dispute led to a mass stabbing. What does this reveal about the roots of youth violence today?