Troutdale - The shooting at an Oregon high school on Tuesday was the third such outbreak of gun violence at a US high school or college in less than three weeks.
A 14-year-old student named Emilio Hoffman was shot dead by a gunman was also found dead in a bathroom stall.
Reynolds High School in the middle-class Portland suburb of Troutdale was immediately locked down, then evacuated room by room, as law enforcement officials converged on the campus of 2 800 students, which had been set for its last day of classes on Wednesday before the summer break.
"A gunman entered the high school this morning, shot one student. Unfortunately, that student has died," Troutdale Police Chief Scott Anderson told a news conference. "The gunman was located and the gunman is also deceased."
Gym teacher and track coach Todd Rispler was grazed by a bullet but made his way to the school's office to initiate the lockdown, possibly saving lives, Anderson said.
Authorities have not publicly named the gunman nor said how he died, but USA Today cited a police spokesperson as saying the shooter was a teenager who shot himself to death in a bathroom stall following the attack.
The violence in northern Oregon was the latest in a string of fatal shootings in US public places since May, including one at a Christian college in neighbouring Washington state last week in which one student died.
President Barack Obama expressed deep frustration on Tuesday at the inability of Washington lawmakers to tighten gun control measures in the wake of US shootings.
"The country has to do some soul searching about this. This is becoming the norm and we take it for granted in ways that, as a parent, are terrifying to me," Obama said in reply to a question at a White House online event.
'This is not a drill'
Oregon lawmakers have been at a legislative impasse for about two years over stricter gun control proposals.
Television footage at the Oregon school showed police officers in helmets and tactical gear stepping from armoured vehicles and running near the school's perimeter with rifles. Students streamed out of the school with hands raised.
A few miles from the school, students bussed from the campus were being reunited with anxious parents in the parking lot of a shopping centre.
"I'm glad it wasn't worse," said Rachelle Rueschenberg, a mother clutching her 9th grade daughter, Maddy.
Two girls from the high school, sisters Kadejah and Deondra Nixon, told Reuters after being reunited with their parents that police were asking students whether anyone had ridden a bus to school with a student carrying a guitar case.
Kadejah Nixon said she did not hear gunfire because the shooting was in a different wing of the building, but recounted an announcement over the public address system that urged students to go to the nearest classroom and close the doors.
"This is not a drill, this is serious, get into a classroom," was the announcement.
Police said during a search of the school after the shooting they found a gun on another person, which they believed to be unrelated to the violence. That person, who was not identified, was taken into custody.