This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

[Breaking news update, published at 2:45 p.m. ET]

A male student opened fire at just after 7:30 a.m. at a Southern California high school, killing a 16-year-old girl and wounding four others, who were transported to hospitals, Los Angeles County Sheriff Alex Villanueva told reporters.

The suspected shooter, who turned 16 on Thursday, was hospitalized with a gunshot wound. Officials said he is in grave condition.

Students are escorted out of Saugus High School after the shooting.

[Previous story, published at 2:29 p.m. ET]

Someone opened fire at a high school in the Southern California city of Santa Clarita before classes began Thursday morning, killing one person and injuring several others, officials said, and sending some students streaming out of the building as others hid.

A suspect in the shooting at Saugus High School is in custody and is being treated at a hospital, Los Angeles County Sheriff Alex Villanueva said on Twitter.

Of six patients taken to hospitals, one has died and two are in critical condition, hospital officials said. At least five were shot, a sheriff’s department official said.

Emergency workers took several people out of the school on gurneys, and large groups of people walked out single-file with armed escorts, aerial footage from CNN affiliates shows.

Officials shepherded students to nearby Central Park, where parents were told to meet them.

Authorities had been looking for a suspect described as a male in black clothing, the sheriff’s department said on Twitter. The suspect is believed to be a student at the school, Villanueva told CNN affiliate KABC.

Details about how the suspect was caught or why the suspect went to a hospital weren’t immediately available.

The shooting happened about 20 minutes before the start of school, according to Hannah de Caussin, whose daughter attends Saugus.

**Embargo: Los Angeles, CA**
Emergency workers took at least three people out of the school on gurneys, and large groups of people have been walking out single-file with armed escorts, aerial footage shows.

Some students fled, and others hid

Some students fled the building immediately, and others took cover inside rooms, another student told CNN affiliate KTLA.

“It was one and then four quick ones, so bang, and then bang, bang, bang, bang,” the girl said after leaving the building.

Students are trained to take cover in classrooms, but she and some others ran out because they thought the shooter was near where they would have hidden, she said.

“We ran through the fence, luckily it was open, and we got as far away from campus as we could,” she said.

“We were texting all our friends and making sure they were safe. They said they were hiding and they were scared. It scared us because they’re our friends and we didn’t want anything bad to happen to them.”

Another student, Brooklyn Moreno, told CNN affiliate KCBS that she was waiting for a bell to ring to signal her first class when she heard the first shot.

“Everyone thought it was a balloon, and it got really quiet. And then two more shots, and then everyone just ran out of the school,” said Brooklyn, who added that she ran across a street to someone’s house until someone came to pick her up.

Grandfather: Students ran down my street screaming

Larry Everhart, a grandfather of a Saugus High student, told KCBS that he was leaving his house to get coffee when he saw students running down his street screaming.

“They were saying, ‘Can I come in your house?’ It was about 20 of them. I wanted to make sure they were safe, so I got them in there,” he said.

School officials are sending students to Central Park, where parents should meet them, the district said.

Everhart’s neighbor, a police officer, eventually told him he could go to the park, where he found his granddaughter safe.

“My granddaughter threw her arms around me and was hugging me, and I was just so happy she was still alive,” he said.

Rumors of online threats are being investigated

Investigators will check rumors that the suspect may have posted threats on social media, county Undersheriff Tim Murakami said on Twitter.

“If you ever learn of posted threats please notify us ASAP,” Murakami wrote.

All schools in Santa Clarita’s William S. Hart school district were temporarily locked down as a precaution, but the restrictions were later lifted, the district said.

Saugus High School, about 30 miles northwest of Los Angeles, has about 2,400 students, according to the district.