PARKLAND, Florida - State flags in Florida are at half-staff Thursday in memory of those who died in the Stoneman Douglas High School shooting. At least 17 were killed in the rampage. The suspected gunman was identified as Nikolas Cruz, a 19-year-old who had been expelled from the school.

We now know student Jamie Guttenberg and assistant football coach Aaron Feis were both killed in the shooting, reports CBS News correspondent Manuel Bojorquez. Broward County Sheriff Scott Israel confirmed Wednesday night that a football coach was killed and the son of a sheriff's deputy was shot and is in stable condition.

"I don't know how we're alive," freshman Bruna Aleveda said. She and her classmates witnessed their teacher get shot, she told us. 

"For like 30 minutes, we were just like praying and crying and – and then the police came and we just got out," Aleveda said, choking up with emotion.

Students and teachers barricaded themselves inside classrooms to take cover. 

"We were in code red. We were in lockdown in the corner of the room. It was awful," one woman said. 

Sophomore Nicole Healy describes the carnage she saw as SWAT members led them to safety.

"On the way from getting evacuated, you saw two dead bodies on the floor," Healy said.

There were tearful reunions as loved ones arrived on-scene to make sure their children were OK.

"I certainly feel for the children who lost their lives and the parents of those children because I'm one of these parents and certainly not feeling so good right now," one mother said emotionally.

"I'm absolutely sick to my stomach to see children who go to school, armed with backpacks and pencils, lose their lives," Israel said.

Senior Hector Navarro escaped the gunfire through a field with a group of more than 50 students.

"I ran as fast as I could. I made sure all my friends were around me and just made sure we were all safe," Navarro said.

He believes one of his friends is among the victims.

"It hit very close to home," Navarro said. "It's not easy but I know together as a family and as a school, as a whole we can get through it."

Officials aren't releasing the entire list of victims' names until all the families have been properly notified.

President Trump offered sympathy on Twitter, adding, "No child, teacher or anyone else should ever feel unsafe in an American school."