A man in his 20s died at the hospital and a critically injured 20-year-old woman was taken to surgery, Harborview Medical Center spokeswoman Susan Gregg said. A 24-year-old man and a 22-year-old man were in satisfactory condition. None of the victims was immediately identified.
The afternoon shooting came a week before the end of the school year, and the situation was particularly tense when police initially reported that they were searching for a second suspect. They later said no one else was involved.
The university locked down its campus for several hours, and alerted students and staff to stay inside. Some students were taking finals in the same building where the shooter was.
The school canceled classes Thursday evening, and planned to hold a prayer service.
"We're a community that relies on Jesus Christ for strength and we'll need that at this time," said Dan Martin, president of Seattle Pacific University, which is located at the edge of a leafy Queen Anne neighborhood about 5 miles from downtown Seattle.
Martin choked up when he talked about the student who put himself in harm's way to protect others.
Jillian Smith was taking a math test on the second-floor of Otto Miller Hall when a lockdown was ordered.
She heard police yelling and banging on doors in the hallway. The professor locked the classroom door, and the 20 or so students sat on the ground, lining up at the front of the classroom.
"We were pretty much freaking out," said Smith, 20, a sophomore. "People were texting family and friends, making sure everyone was OK."
Smith said they sat in the classroom for about 45 minutes, before police came and escorted them out of the building. On the way, they passed the lobby where she saw bullet casings and what appeared to be blood in the lobby carpet and splatter on the wall.
"Seeing blood made it real," Smith said. "I didn't think something like this would happen at our school," she added.
Ashley Springer, 26, was in a classroom with her professor and a few other students when a woman with a bullhorn came into the room and told them to lock the door, pull down the shades and turn out the lights.
Springer, a senior, called PLU "a really close community."
David Downs, a 22-year-old senior who is graduating next week, said he had just left campus 30 minutes before the shooting.
"I'm in utter shock," said the Seattle Pacific basketball point guard player. "It's so unbelievable to me that this could happen on our campus. It's the last thing I would have ever thought could happen here."
"It puts things in perspective," he said. "Anything can happen, even on a small Christian campus."
The incident follows a spate of recent shootings on or near college campuses.
Last month, according to police, Elliot Rodger killed six people and injured seven before turning his gun on himself in a rampage in Isla Vista, California, near two universities.
Seven people were killed and three injured when a 43-year-old former student opened fire at a tiny Christian school, Oikos University, in Oakland, California, in 2012. A gunman killed five people and injured 18 when he opened fire in a Northern Illinois University lecture hall in 2008.
In 2007, 32 people were fatally shot in a dorm and classroom at Virginia Tech in Blacksburg, Virginia before the gunman, Seung-Hui Cho, killed himself.
AP reporters Donna Gordon Blankinship contributed from Seattle, and
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