A 16-year-old boy was hospitalized in stable condition Wednesday after being stabbed by another youth during a fight in a Fairfax County, Virginia, high school, authorities said.

The stabbing occurred shortly after 9:30 a.m. in West Potomac High School in the county’s Alexandria area, police and public school officials said. They said the alleged assailant, a 15-year-old boy whose name was not made public, was arrested and charged with malicious wounding.

Police said the two students got in a fight inside the school, which led to the stabbing. Although the victim’s injuries were initially described as life-threatening, he was in stable condition later Wednesday, police said, adding that officers recovered a knife after the incident.

A third student involved in the fight has not been charged, police said. They said no other suspects are being sought.

“While there’s a sense, obviously a shock, that this would happen … I’m very proud of the response of our staff to this incident,” the county schools superintendent, Michelle Reid, said at a news briefing. “They responded quickly and admirably and may have saved a life today.”

Authorities did not share details on what caused the fight but said the two students know each other. They said more information would be shared later.

In a Facebook post, the West Potomac High School Parent Teacher Student Association said the school was placed on a “Stay Put, Stay Tuned” safety protocol following the incident. Police said an officer assigned to the school reached the stabbing scene within seconds and that other officers arrived at the school within minutes.

Reid said students at West Potomac finished the school day. Counselors and additional resources were brought into the school for students who witnessed or were affected by the stabbing.

“I’ve met with several classes, talked with students, talked with staff this morning, and there’s obviously a commitment to continuing to move forward,” Reid said. “We’ve got a lot of weeks left in the school year, and we hope that today’s incident was very isolated.”

Virginia state Sen. Scott A. Surovell (D-Fairfax), the majority leader, who has a son attending West Potomac, decried the violence in a statement, joined by state Del. Paul E. Krizek (D-Fairfax).

“These students are so close to the end of the school year and, for many, a graduation,” Surovell said. “This time for celebration is now marred by this ugly incident. These kids deserved so much better today.”

School officials said they did not cancel classes because they wanted to maintain a sense of calm and prevent young people from going into the community unsupervised. They said they did not want to “release emotional students and then have something retaliatory in nature happen down the street.”

However, Reid said, the school planned to begin an early-dismissal process later Wednesday for parents who wanted to remove their children from the school.

By noon, dozens of anxious parents had gathered outside of the school, frustrated and angry that they weren’t able to check on their children. One parent, Bill Beal, said he received photos from his daughter of a young boy lying bloodied on the floor around 9:45 a.m., shortly after the stabbing. His daughter, a freshman, was “freaking out,” he said.

Beal immediately headed to the school, desperate to see his daughter and confirm she was safe.

He had already arrived by 10:15 a.m., when the school system sent out its first alert informing parents that the school had been placed in a “Stay Put, Stay Tuned” status. At first, Beal said, he didn’t worry because he knew that under this protocol, parents with proper identification are allowed to check out their children.

But when he tried to do that, he was stopped. “I just want my daughter,” Beal said. “My 14-year-old girl is freaking out right in there and I can’t get to her.”

Earlier this month, the school district began a weapons detector pilot program. Starting this week, the detection system — walk-through gates that electronically scan students for weapons — will be deployed each week to a randomly selected high school for morning arrival. According to the school system, the detectors might be in place for one or several days. The detectors were not in use Wednesday at West Potomac.

Similar systems has been used in other school districts around the region. Prince William County Public Schools, the second-largest district in the state, after Fairfax, signed a $10.6 million, four-year contract in 2023 to deploy such scanners in its middle and high schools.

The scanners can act as a deterrent but have also been criticized for shortcomings in catching some weapons, especially smaller knives. In 2022, a student in Utica, New York, made it through similar detectors with a knife and stabbed another student multiple times during a hallway fight.

Aellene Fernandez watched a video that her son, a West Potomac freshman, sent her of the fight and wondered whether she would send him back to school on Thursday.

“I need action” to improve school safety, she said. “A kid having a knife in school hours, that makes no sense to me.”