A discarded piece of police tape sits near a memorial at the scene of the shooting at Seattle Pacific University. (David Ryder/Reuters)

The day after a gunman opened fire on the campus of a small university in Seattle, killing one person, two students remained hospitalized and the school was still closed.

A gunman, identified by Seattle police as 26-year-old Aaron R. Ybarra, walked into Otto Miller Hall on the Seattle Pacific University campus shortly before 3:30 p.m. and began firing a shotgun. One student, a 19-year-old man who has not been publicly identified, was killed. Two other students were injured, one of them critically.

When the gunman stopped to reload his weapon, a student building monitor pepper-sprayed him and tackled him, according to Seattle police. They also said several other bystanders also helped hold down the shooter until police arrived a few minutes later.

The school building monitor has been identified by local media outlets as Jon Meis, a 22-year-old engineering student. He has been praised by friends as selfless and courageous. Meis has not spoken with the news media yet, and a family member told the Seattle Times he would not be commenting right now.

In addition to the shotgun, the shooter also had a knife and additional ammunition, police said. No motive has been released by authorities yet, and police said they haven’t found any connection yet between the shooter, the university or any of the victims.

“This is a tragic moment for Seattle and a tragic moment for America once again,” Seattle Mayor Ed Murray (D) said during a briefing with reporters on Thursday.

This shooting caused panic and confusion across the campus of Seattle Pacific, a small Christian school located about 10 minutes away from downtown Seattle. Buildings were locked down and students ordered to shelter in place and stay away from windows, a scene that has played out time and time again on campuses and other places across the country.

“It was super-terrifying,” Kharis Lund, a sophomore, told the Seattle Times. “There were a lot of people crying and calling their parents.”

As police teams checked out buildings across the campus, which has about 4,200 students, they continued to find students and faculty members hidden in offices and sheltered in classrooms.

The school goes through security drills for events like this, and university president Daniel J. Martin said Thursday he believed these drills “did make an impact” in how quickly people reacted to the shooting.

Thursday’s shooting was the latest in a seemingly endless succession of violent episodes that regularly grip our schoolsshopping mallsmovie theaters and other quotidian locations. It came less than two weeks after a college student opened fire in an area near the University of California Santa Barbara. (Here’s a look at what kinds of guns are used in mass shootings.)

“To see gun violence erupt at a place of higher education shocks all of us,” Washington Gov. Jay Inslee (D) said in a statement. “Our schools should be safe havens. And so should our homes, our streets and our workplaces. We need to do more to prevent violence throughout our state.”

Seattle police had said in the wake of the shooting that four people were shot and taken to the hospital. They amended that later to say that three people were shot and the fourth person suffered minor injuries during the struggle to restrain the gunman.

Susan Gregg, a spokeswoman for Harborview Medical Center, said in a news conference Friday that this fourth person was “the one who apprehended the shooter.” He has since been released from the hospital.

Meanwhile, the two other victims remained in the hospital on Friday. A 19-year-old woman was in critical but stable condition; she was shot in the chest and abdomen, requiring five hours of surgery on Thursday, Gregg said.

The other victim, a 24-year-old man, was hit by pellet fragments in his neck, chin and his upper extremities. Gregg said he is in satisfactory condition and could leave the hospital as early as Saturday.

“All these patients and their families are going through a lot of mental trauma,” she said.

Police had noted shortly after the shooting that they were dealing with conflicting information, which resulted in uncertainty about the number of victims and suspects. This is a fairly common occurrence immediately after a shooting, as it can take authorities time to clear the scene and determine what happened. In this case, police were told there was a potential second suspect, though they later determined that there was only one gunman.

Otto Miller Hall, a science and engineering building, will remain closed indefinitely, according to the university. All classes and previously scheduled events were canceled Friday, while a prayer service was set for noon at the First Free Methodist Church on campus.

Students gather in a prayer circle after the shooting. (Elaine Thompson/AP)