Castle View Elementary School in Riverside had been evacuated Tuesday after a parent having a "breakdown" assaulted a staff member and barricaded himself in a classroom with a teacher, officials and witnesses said.
Children and staff members were safely evacuated from the school, and no additional injuries were reported.
The barricade ended more than six hours later as a SWAT team made entry using flash-bang grenades around 5:50 p.m.
Officers shot the suspect and he was seen being taken away on a stretcher. He later died at a local hospital, officials said.
The suspect was identified as Luvelle Kennon, 27, of Riverside.
The teacher had only minor injuries and was taken to a local hospital as a precaution.
The suspect had been carrying a backpack, but no weapon was seen, officials and witnesses said.
VIDEO: Riverside barricade suspect's family speak out
The incident began when Riverside police responded to the school following a report about some sort of disturbance on campus around 11:12 a.m.
The suspect apparently had an altercation with a staff member in the office. A man described as a substitute teacher who is also the husband of a staff member tried to intervene and was assaulted. He was seen later with blood on his shirt and an apparent broken nose.
"This person is also a hero," said Officer Ryan Railsback with Riverside police. "He did everything he could to try to prevent the suspect from taking the teacher into the classroom and being held hostage, to the point where he got hit in the face pretty good. He might've had his nose broken from that."
The suspect then went into the classroom and barricaded himself inside with a female first-grade teacher, holding her hostage.
The hostage was identified by her daughter as 70-year-old Linda Montgomery, who has taught at the school for decades.
"She loves teaching," said her daughter, Michelle Montgomery.
Family members of the suspect said he has a daughter in first grade at the school. They say he had some kind of breakdown in the morning and other family members took away his car keys, but he was able to get to the school anyway.
"He had a breakdown, and he relapsed again. That's all, he's not dangerous," said Carl Jackson, who identified himself as the suspect's uncle. "It's just a matter of getting in there and talking to him, because we can talk to him. He'll come out for us if police let us, before anything bad happen to him."
Jackson described his nephew as "not a bad guy, never been in trouble."
"He's a good kid, just having an emotional breakdown. He doesn't have no access to no weapons," Jackson said.
Police said they did observe some smoke coming from the room at one point, but there were no indications of a device or a toxic material and the smoke later dissipated.
"When officers did respond, they noticed some type of smoke coming from the room," said Officer Ryan Railsback with Riverside police. "They don't believe it was related to any type of explosive device. We don't know."
"It didn't seem anything toxic that was harming anybody. We don't know if it was even maybe a fire extinguisher. But it looks like it since dissipated. It didn't seem to be too much of a concern other than it came from the room they were in."
SandiKay Barber-Alvarez, a parent of a sixth-grader who attends Castle View, told Eyewitness News she rushed to the campus as soon as she heard all the commotion.
That's when she saw the substitute teacher with a broken nose and blood running down his shirt being escorted to an ambulance.
Barber-Alvarez was later reunited with her daughter, Madison, who described what it was like to be under lockdown in her classroom.
VIDEO: Riverside mom, daughter reunited amid possible hostage situation
"I felt like that this is so terrifying. I thought this going to be my worst nightmare I've ever had," she said.
The 12-year-old said her teacher continued to assure her and her classmates that they were all going to be safe.
"We were praying that we're going to be OK," Madison said, adding that they were on lockdown for two hours before police officers came into her classroom.
That's when the students were evacuated from campus.
The students were evacuated to nearby Castleview Park and were all safe and accounted for, Riverside Unified School District officials said. School officials worked to reunite the students with their parents.
VIDEO: Riverside police provide update on school barricade situation