SEATTLE — 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 (thegunman) stepped up.”

A 19-year-old man was fatally shot and two other young people were wounded after the gunman entered the foyer at Otto Miller Hall on the Seattle Pacific University campus 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.

The man in custody was not a student at the school, McDonagh told a news conference.

Four people, including the young man who died, were taken to Harborview Medical Center. A critically wounded 20-year-old woman was in intensive care late Thursday after 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.

Aaron R. Ybarra, 26, was booked into the King County Jail late Thursday for investigation of homicide, according to police and the jail roster.