Students hold their hands in the air as they are evacuated by police from Marjorie Stoneman Douglas High School in Parkland, Fla., on Wednesday..
Here is what we know about the victims who have been identified by ABC News.
Aaron Feis, the football coach and security guard at Marjory Stoneman Douglas High School who stepped in front of a spray of bullets during Wednesday's mass shooting, has died, according to the football team's Twitter account.
"He was a great guy", said Gage Gaynor, a sophomore lineman.
"I heard Aaron say, "No, that is not firecrackers", May told the Sun Sentinel of Feis" response to the initial call on the school's security walkie-talkies.
"It is with great sadness that our football family has learned about the death of Aaron Feis", the tweet read. He suffered a gunshot wound and later died after he was rushed into surgery, Lehtio said. His older brother Miguel, who graduated from the same school past year, wrote on Instagram, "Words cannot describe my pain". "I love this man with all my heart". "He was always so nice to me when I went to school there, and I know he is close with my brother and his friends". JOAQUIN OLIVERJAMIE GUTTENBERGJamie was a student at the school.
"He opened the door for [a student] because the shooter was right behind her, and getting into the room he tried to block all the students and ended up getting shot but he locked the door", one student said. We lost our daughter and my son Jesse Guttenberg lost his sister. "I am broken as I write this trying to figure out how my family get's through this", he wrote.More news: HTC's smartphone president has resigned following ten quarters of losses
Feis died protecting students.
"I had thought he was behind me ... but he wasn't", Friend said, crying. "And then I saw the shooter run after Mr. Feis, and I saw Mr. Feis get shot", she said. Subsequent posts said he was wounded but had initially survived the shooting. Check back for more details about the victims as we learn them.
"(He) made sure everyone else's needs were met before his own.
"It is so senseless", he added.
He had been expelled from the school after being identified as a threat previous year, and was attending another school at the time of the shooting.
The school will be closed the rest of the week.