PARKLAND: A former student armed with an AR-15 rifle opened fire at a Florida high school on Wednesday, killing at least 17 people, officials said, in a harrowing shooting spree that saw terrified students hiding in closets and under desks as they texted for help.
Broward County Sheriff Scott Israel identified the gunman as Nikolas Cruz, 19, a former student at Marjory Stoneman Douglas High School in Parkland who had been expelled for "disciplinary reasons."
Cruz was arrested without incident in the nearby town of Coral Springs after the Valentine's Day rampage and taken to hospital with minor injuries, the sheriff said.
"We have already begun to dissect his websites and things on social media that he was on and some of the things... are very, very disturbing," Israel said.
"He had countless magazines, multiple magazines, and at this point, we believe he had one AR-15 rifle," the sheriff added.
My prayers and condolences to the families of the victims of the terrible Florida shooting. No child, teacher or anyone else should ever feel unsafe in an American school.
— Donald J. Trump (@realDonaldTrump) February 14, 2018
Israel said both students and adults had been killed. He was uncertain about the exact number of people injured, but at least 14 were taken to hospital and two had died there of their wounds.
The shooting, one of nearly 20 since the start of the year, will once again throw the spotlight on the epidemic of gun violence in the United States and the ready accessibility of weapons in a country with 33,000 gun-related deaths annually.
"This is a terrible day for Parkland," Israel said, speaking of the city of about 30,000 people, located 50 miles (80 kilometers) north of Miami.
"My very own triplets went to that school."
A teacher at the school told The Miami Herald that Cruz had been identified previously as a potential threat to his classmates.
"We were told last year that he wasn't allowed on campus with a backpack on him," math teacher Jim Gard said. "There were problems with him last year threatening students, and I guess he was asked to leave campus."
Cruz was also said to have been in the Junior ROTC (Reserve Officers' Training Corps) program while at school.
A law enforcement source told CBS News that the gunman pulled a fire alarm before opening fire, but Israel said he could not confirm that report.
'Everyone started running'
Student Jeiella Dodoo told CBS News that she and her schoolmates had evacuated their classroom calmly after hearing what they thought had been a routine fire alarm.
"The alarm went off so we had to evacuate from our classes," she said. "Then we heard gunshots.
"I heard about six gunshots," she said, "and then some people started running and then everyone started running because we were like 'If it's real, then just run.'"
Just spoke to Governor Rick Scott. We are working closely with law enforcement on the terrible Florida school shooting.— Donald J. Trump (@realDonaldTrump) February 14, 2018
A math teacher at the school told CBS that he was hiding with six of his students.
"We are fine. We are waiting," he said.
Caesar Figueroa told CNN his daughter was hiding in a closet and texting her family.
"She's trapped with her 10 friends. She said she heard gunshots. A window blew and everybody is screaming and running, and she said she ran in the closet and she's still there," Figueroa said.
No child should 'feel unsafe'
"My prayers and condolences to the families of the victims of the terrible Florida shooting," President Donald Trump said on Twitter.
"No child, teacher or anyone else should ever feel unsafe in an American school."
Since January 2013, "there have been at least 283 school shootings across the country -- which averages out to one school shooting a week," according to Everytown for Gun Safety, a non-profit group that advocates for gun control.
Since the 2012 massacre at the Sandy Hook Elementary School in Newtown, Connecticut, where 20 children and six adults were shot dead, warning procedures and emergency drills have multiplied at US schools.
The goal is to teach school children how to react to a shooter who opens fire at random.