When a lone gunman armed with a shotgun at a small Seattle university stopped firing at students to reload, another student pepper-sprayed him and subdued him with the help of others and prevented more deaths, police said.

"There are a number of heroes in this," Assistant Police Chief Paul McDonagh said. "The people around him (the gunman) stepped up."

A 19-year-old man was fatally shot and two others wounded after the gunman entered the foyer at Otto Miller Hall at Seattle Pacific University, a non-denominational Christian school, and started shooting Thursday afternoon. When he paused to reload, a student building monitor disarmed him. The gunman had additional rounds and a knife, McDonagh said.

"But for the great response by the people of Seattle Pacific, this incident might have been much more tragic," he said.

Aaron R. Ybarra, 26, was booked into the King County Jail late Thursday for investigation of homicide, according to police and the jail roster. He was not a student at the school, McDonagh said during a news conference.

Four people, including the young man who died, were rushed to Harborview Medical Center. A critically wounded 20-year-old woman was in intensive care late Thursday night after about five hours in surgery, hospital spokeswoman Susan Gregg said. A 24-year-old man was hospitalized in satisfactory condition. A Seattle Fire Department official said the man suffered "pellet type wounds" to his neck and chest.

A 22-year-old man was treated and released, Gregg said. Police said he suffered minor injuries during the struggle with the suspect.

None of the victims was immediately identified.

Also late Thursday, police who said they were serving a warrant entered a house that was believed to be tied to Ybarra. A phone message left at that house in the north Seattle suburb of Mountlake Terrace was not immediately returned.

According to TV station Q13 Fox, the shooter lived in the house with his mother.

Messages left with friends and relatives of Ybarra via social media were not immediately returned.

The Seattle Times reported that the suspect's father, Ambrose Ybarra, said he doesn't know anything of the incident.

"We just hope he's safe," he told the newspaper. "It's upsetting to have these accusations thrown around. We're in emergency mode. We are trying to stay calm."

Annie Nguyen, a former coworker of Ybarra's at a gym, told Q13 Fox that the suspect “was an amazing friend. Good worker. He was really calm and nice. If you know him, you would not think he would do it.”

Nguyen described Ybarra as being very sociable, someone who liked to go out to bars with people from work. She said that he told her he liked to go to a shooting range, and once invited her to come along.

The paper said Zack McKinley described himself as one of Ybarra's closest friends and said he was "super happy and friendly."

McKinley said the attack was puzzling because Ybarra was happy to have just started a new job bagging groceries at a store.

He said Ybarra didn't do drugs or drink alcohol and spent time writing. Ybarra could get emotionally low, but McKinley said he had a good group of friends and never saw him depressed.

Student Chris Howard was at Otto Miller Hall when the shooting happened. He said he saw the wounded young woman on the floor being tended to by a classmate. Her chest was bloodied. Her phone was covered in blood, but she asked her helpers to look through her phone for her mother, aunt and best friend.

"She was panicking," Howard said. "She said 'I think I'm going to die.'"

Both the young man who died and the young woman suffered gunshot wounds to the body, Seattle Fire Assistant Chief Jay Hagen said during a press conference.

On Thursday evening, people packed the First Free Methodist Church on campus for a service of prayers and song. So many people crowded into the building that dozens of people gathered on a lawn near the church and formed their own groups as the sun set.

"We're a community that relies on Jesus Christ for strength, and we'll need that at this point in time," said Daniel Martin, university president.

About 4,270 undergraduate and graduate students attend the private Christian university. Its 40-acre campus is in a leafy residential neighborhood about 10 minutes from downtown Seattle. The school canceled classes and other activities Friday.

Based on reporting by the Associated Press.

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