By Kirk Johnson

New York Times News Service

SEATTLE — A man armed with a shotgun opened fire on the campus of Seattle Pacific University on Thursday afternoon, leaving three people wounded and one dead before being taken into custody, the Seattle police said.

The police said that the gunman had stopped to reload before he was pepper-sprayed by a student security guard and subdued at a science and engineering building. Witnesses described scenes of blood and panic, and frantic cellphone calls to loved ones. But the episode was over quickly.

A spokeswoman for Harborview Medical Center, Susan Gregg, said a 20-year-old man arrived at the hospital in critical condition and died shortly afterward. A 20-year-old woman was in critical condition, Gregg said, and two other men, ages 24 and 22, were in satisfactory condition. One of the men’s injuries did not involve gunshot wounds, but no other details were available.

No names were released, and the police did not say what led to the shooting.

Chris Howard, a 22-year-old mechanical engineering student, found himself cradling one of the victims, a young woman he did not know, with her head on his lap as responders surged to the scene. He took her cellphone, he said, and tried to reach her mother and her aunt, but got only voice mail.

“There was a lot of blood on her chest,” he said. “There appeared to be a tourniquet on her arm.”

The school, which was founded in 1891 by Free Methodists and promotes a Christian educational outlook, has about 4,000 students on a 40-acre campus about 10 minutes from downtown. Buildings went into lockdown as emergency responders arrived at the scene, Otto Miller Hall, which houses science, engineering, mathematics and physics classrooms. The police, posting updates on Twitter soon after the shootings, said a second suspect was being sought, but minutes later said there were “no outstanding suspects.”

All classes and activities on campus scheduled for today were canceled.

One student, Jordan Heff, told The Seattle Times: “I was in physics, and people heard a loud bang — we thought it was a science experiment. We heard crying and yelling outside our door. We walked out, and there were bloodstains all over the carpet.”

Howard, the engineering student, said he also saw a man being held down and questioned by the police, who asked him whether there were others involved, to which the man said no. He described the suspect as in his mid-30s.

“He seemed kind of calm,” Howard said.