PARKLAND, FLORIDA (Fort Wayne's NBC) -- Here is the latest information on today's deadly high school shooting in South Florida from NBC News.

We will have the full story and a related story from Fort Wayne about how parents can talk to their children about the tragedy tonight at 11 on Fort Wayne's NBC News.

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At least 17 people were dead after a 19-year-old man opened fire at Marjory Stoneman Douglas High School in Parkland, Florida, on Wednesday afternoon, officials said.

At least 16 other people were wounded, five of them with life-threatening injuries, hospital officials said. The suspected gunman, identified as Nikolas Cruz, was also wounded but was released from the hospital and was in custody, authorities said. Broward County schools Superintendent Robert Runcie said Cruz had recently been expelled from Douglas for disciplinary reasons and was currently enrolled in another school in the district.

"You come to the conclusion this is just absolutely pure evil," Florida Gov. Rick Scott, his hands clutched over his chest, said Wednesday night.

Broward County Sheriff Scott Israel, who told reporters Wednesday night that the son of one of his deputies was among the injured, said Cruz was believed to have been armed with a AR-15-style semiautomatic rifle and multiple magazines. Israel He said it was unclear whether he had any other weapons.

The gunfire began outside the school and continued inside, where 12 of the victims were killed, Israel said. All of those victims have been identified, he said, but no identities will be made public until the families of all of those affected have been notified.

Federal and local authorities told NBC News that there was no indication that the gunman had an accomplice or accomplices.

Cruz was taken into custody off campus about an hour after he "committed this horrific, detestable act," said Israel, who said investigators were reviewing social media postings that he described as "very disturbing."

Eddie Bonilla, a senior, told NBC Miami that Cruz was "a little bit off" and "troubled."

Cruz used to show off his guns, brag about shooting them "for fun" and "threatened to bring the guns to school multiple times," he said, adding that students "threw jokes around that he'd be the one to shoot up the school."

Sebastian Toala, another senior, told the station: "I never really got close to him because I always had a feeling there was something wrong."

Parkland, in north Broward County, is about 30 miles northwest of Fort Lauderdale. The shooting on the sprawling campus happened despite the presence of police officers at the school.

Broward County schools Superintendent Robert Runcie said at last two police cars were typically on campus "on a daily basis."

While students filed out of the school with their hands up, heavily armed SWAT team members conducted a class-by-class search to make sure there were "no other shooters" — and to retrieve any bodies, he said.

Israel, who said his triplets once attended that school, urged worried parents to head to a nearby Marriott hotel to collect their children.

"This is a terrible day for Broward County, the state of Florida, the United States," he said. "There really are no words."

The first sign that something awful was happening came around 2:30 p.m., not long before classes were supposed to have been dismissed, when authorities were called to respond to an active shooter.

For more than an hour, the school was at the mercy of a gunman on the loose.

"He was outside and inside the school," Israel said.

Just after 4 p.m., the Broward County Sheriff's Office announced on Twitter that the suspect had been apprehended.

Not long after, stunned survivors began sharing their accounts of what happened.

"I was on the first floor of the building where the shots happened first," freshman Jason Snytte told NBC News. "I was in the classroom right next to the outside, the closest classroom to it. It started there. I heard six or seven shots. Our door was open. I ran and closed it, and everybody ran into a corner."

Jason, who said the shots were deafening, said they listened to their teacher and stayed put until police arrived and told them to evacuate.

"We were all freaking out. Our hearts were racing," he said. "We didn't know what was happening."

Several students told NBC News that the school had gone through a fire drill earlier in the day. They said the fire alarm sounded again just before the shots were heard.

Relieved parents like Lisette Rozenblet, whose daughter attends the school, also said she was told that a fire alarm was pulled about the time the shots began. But her daughter's teacher, sensing that it might be a trap, told the students to stay in the classroom, she said.

"Her biggest fear is a school shooting," Rozenblet said of her daughter. "She is always begging me to be home-schooled because she was scared of this."

Joel Leffler, whose son and daughter attend the school, said both of his kids were safe — but in shock.

"My son called me as it was unfolding, running. He had to jump a fence," Leffler said. "My son heard around eight gun shots as he was running out."

When he reached his daughter by phone, she was whispering, he said.

"My daughter, who was there in the freshman hall where the shooting took place — she's in shock right now, and she's being taken out by SWAT," Leffler said. "She saw multiple dead bodies."

President Donald Trump was briefed and was monitoring the situation, White House Press Secretary Sarah Huckabee Sanders said.

Scott traveled to Broward County to be briefed by emergency management officials and law enforcement. The governor said he had been in touch with Trump and the Department of Homeland Security.

Scott didn't address reporter's questions Wednesday night about whether the gunman should have been able to obtain a semiautomatic rifle.

The governor, a Republican who has an "A+" rating from the National Rifle Association's Political Victory Fund, said: "There is a time to continue to have these conversations about how, through law enforcement, how through mental illness funding, to keep people safe, and we'll continue to do that."

"This is just, this is just pure evil," he said.