Transcript for 17 confirmed dead in Florida school shooting, suspect in custody
We could see the panic from a distance. Frightened. Reports are just coming in. Don't have a lot of information. We didn't know the who butal of us feared the what. There's an active shooter situation situation in south Florida. Oh, my god! That rapid roar of death and dieing. In another American school. Does he know where the shooter is. We don't know but we're heading into the building. The first 911 calls came just before Marjory Stoneman Douglas high school led out for the day. Police FBI and ATF all descended on the scene. We can't get hold of her. Have you called and texted and nothing has come back. Girlfriend got shot we heard. There was panic. Confusion. Parents desperate to find out had their child survived. It's devastating. I'm sick to my stomach. A line of ambulances in place of the school busses. We were just praying and crying, and I don't know how we're alive. Hours go by. Students finally reunited with their family and by evening 17 dead, 14 injured, and former student Nikolas Cruz who can stole so much from so many. Come to the conclusion this is absolutely pure evil. Students detailing those traumatic moments from inside. All we heard was the gunshots. We heard the gunshots and hid in the tennis courts. Talking about what they did as gunfire echoed in the hallway. Heard like a garbage truck banging. We hear boom, boom, boom hear screaming and we jumped under hi teacher's desk. Swat teams searched the perimeter. Moner titorin the subject. He went from the third to second floor. May have a gas mask on. Students barricading in classrooms, closets, anywhere they could hide. Need everyone down. As officers go room to room. Put phones away. Some recording disturbing videos of the mayhem many texting their parents. She keeps telling me be safe stay away. I'm telling her no I'm your mother I'm not staying away. Outside high schoolers streaming out of the building hands over their hands for safety. Just after 3:00 P.M. The shooter is still at large. White male. Burgundy shirt wearing black hat or long black pants mixed in with a group of students running west bound. Authorities said he got out of the school by blending in with others who were trying to escape. It's not uncommon for thieves, like robbers, to try to blend in with the crowd and try to escape. Somewhat unusual with mass shooters because vast majority of time they kill dhem selves or force law enforcement to kill them. Students outside, breathless, heart wrenching reunions, others waiting for answers, some student and staff unaccounted for. What did she fell you. She's crying. Can't say anything. She's crying a lot. This student recalls seeing teacher shot. We saw his body for like 30 minutes. We were just like praying, and crying and, then the police came and we just got out. This is the day we prayed would never be here in Broward county but we're going to deal with it as a community. Around 4:00 P.M. The alleged gunman taken down in this video, sourced identified him as 19-year-old former student Nikolas Cruz. He was a former student of Douglas high school he got expelled, I don't know the specifics. The school represented something to the shooter. This is not the first time this has happened. Think of Adam at sandy hook who walked into elementary school he attended years before, because there was something about that school that he wanted to destroy. Sadly, he did. Tonight new information about at ledged shooter, a family member telling a brb C news, Cruz was adopted with his younger brother both parent noise deceased. A former class mate called him quiet. That he had a interest in weapons. I knew he was into guns. Last year had a lot of conflicts in school. Got in a fight with one kid and wasn't allowed to bring his backpack because they found bullet casings in it. I told my parents last year every week I was scared this kid might go something. If you take somebody's access to firearm and the fact they talk about fighting or have been in fights now you start to put the pieces together and connect the dots of an individual who may have predisposition to commit an attack like this. Authorities say the suspect used an assault rifle and began shooting outside before continuing inside. He had multiple Mack zeens. Magazines. And one ar 15 rifle. Sound liekz a fire alarm was tripped. Big question will be whether the suspect triggered the fire alarm, if that was done to get the students to come out of the building and then the suspect was then starting to shoot at the innocent students coming out that would indicate there was planning on his pard. Today's shooting marks the 18th school shooting this year in a nation with average of 300 mass shooting each of the last three years. That's at least four shot in each incident. Too soon since the mourning of Las Vegas those that were killed in the church in Texas. As a parent it scares me to death that this body doesn't take seriously the safety of my children. Connect senator Chris Murphy who represented the state sandy hook happened five years ago was on the floor when news broke about today's killings. It only happens here not because of coincidence, not because of bad luck, but is a consequence of our inaction. President trump also responding, tweeting no child, teacher, or anyone else should ever feel unsafe in an American school. No parent should ever have to send their kids to school and have them not return. That shot not happen. Not in parkland, not anywhere in this country. School shootings are no longer new in America. Each one still numbering. We send our children to school to learn, not to die.
This transcript has been automatically generated and may not be 100% accurate.