(CNN) - Under the rallying cry of #NeverAgain, dozens of students and staff who survived the Florida school shooting departed for the state Capitol, where they hope to speak with lawmakers about school safety and gun control on Wednesday.
"If you're not with us, you're against us," Chris Grady, 19, a Marjory Stoneman Douglas High senior, said before boarding a bus Tuesday. "And you're against saving the lives of innocent children and we are going to be voting you out."
The students arrived with blankets, pillows, sleeping bags, snacks and backpacks to catch buses for the 6½-hour drive from Coral Springs to Tallahassee in what they're calling a first step of a nascent activist movement for change. Some were accompanied by their parents.
"People need to get talking about this," Kai Koerber, 16, said of school shootings. "This is not an issue that needs to recur. It needs to stop with us. ... It's our mission. Everyone here today is here to effect change and put a stop to this."
Instead of waiting for adults and politicians to respond to the mass shooting that killed 17 classmates and teachers last week at the Parkland school near Fort Lauderdale, young survivors are organizing in a wave of impassioned advocacy for gun reform. They've garnered support from other teenagers, their families and teachers.
In Tallahassee, however, members of the state's Republican-dominated House of Representatives voted not to take up a bill that would ban guns classified in the legislation as assault weapons. Instead, the bill will stay in committee.
But committees will not meet again during the legislative session, essentially killing the House bill for this year, said Rep. Kionne McGhee of Miami, the Democratic ranking member.
One of the students on a bus said the setback mattered, "but what we're really focusing on is the easy accessibility" to guns like the AR-15.
"You want both sides to come to an agreement that we limit accessibility," senior Christian Serwinowski, 18, said. "It's about looking at both sides and coming to a compromise."
Freshman Phoebe O'Mara, 15, said she was traveling to the state Capitol for the seven friends she lost in last week's mass shooting.
"They had lives and those lives meant something and they were taken away in a matter of minutes," she said. "I want to go to Tallahassee because this should be the last time that happens."
Jon Faber, a chaperone on one of the buses, said his two sons didn't join the caravan to the Capitol because they will be attending funerals for classmates. One of his son's best friends was still in a hospital recovering from the shooting.
"I'm on a mission to make sure no kid has to be scared they're going to be shot going into a classroom again," Faber said.
In Boca Raton, about 1,500 students walked out of a high school on Tuesday in a sign of solidarity with shooting survivors, according to West Palm Beach County School District Superintendent Robert Avossa. About 300 embarked on a more than 10-mile trek to Stoneman Douglas High in Parkland, though some were picked up by their parents along the route.
"They can change the world, and we can only go with them," Darren Levine, a teacher at the school, said of students at an anti-violence rally Monday.
Andrew Pollack lost his 18-year-old daughter, Meadow, in last week's shooting.
"I'm not gonna let my daughter's death go in vain," he told CNN affiliate WSVN. "I promised all these kids that I've been talking to that they're gonna go to school and they're gonna be safe, and we're gonna have a movement."
Florida Gov. Rick Scott held meetings Tuesday with law enforcement, school administrators, teachers and mental health experts about ways to keep students safe and prevent guns from getting into the hands of people struggling with mental illness. The workshops were livestreamed.
"A tragedy like what occurred in Broward County must never happen again and swift action is needed now," Scott said in a statement. "I am bringing local and state leaders together to find solutions on how to prevent violence in our schools and keep guns out of the hands of mentally ill individuals. This is an urgent matter that we must address quickly."
Scott said he planned to present a proposal for safer schools to the state Legislature by Friday.
"I think it's very important we act with a sense of urgency," he told a law enforcement gun policy workshop Tuesday afternoon. "We have to figure this out. How do we make sure a parent says, I'm comfortable my child is going to school and get home safe?"
The day's discussions ranged from possible changes to Florida's Baker Act -- which allows mental health facilities to hold a person for up to 72 hours for evaluation -- to hiring more school safety officers to stricter monitoring and handling of online threats.
"We're going to get something done," Scott told the law enforcement representatives.
Move to ban "bump stocks": President Donald Trump said on Tuesday he has directed his attorney general to propose changes that would ban so-called bump stocks, which make it easier to fire rounds more quickly.
Reopening the school: The high school will reopen in phases, first to staff members on Friday and then for a voluntary campus orientation open to students and parents on Sunday. The "goal is for classes to resume at Marjory Stoneman Douglas High on a modified schedule" on February 27, according to a Broward County Public Schools statement.
Shooter's weapons: The shooter, Nikolas Cruz, had obtained at least 10 firearms, all of them rifles, a law enforcement source briefed on the investigation told CNN. Investigators are trying to track the purchases, which Cruz appears to have made in the past year or so, the source said.
Cruz bought two weapons from Gun World of South Florida in Deerfield Beach, said Kim Waltuch, the store's CEO. She would not provide details on the types of guns he purchased or on the time frame but said the sales team followed normal protocol for Florida firearms purchases. Remembering the victims: Funerals and viewings were held for several victims Tuesday. The US Army said it awarded three victims in the school's junior ROTC program -- Alaina Petty, Peter Wang and Martin Duque -- with Medals for Heroism for their "acceptance of danger and extraordinary responsibilities."
A run was held Tuesday in memory of teacher and cross-country coach Scott Beigel, who was killed as he tried to usher students back into his classroom when the shooting broke out.
Report: Cruz came to state agency's attention
More details have emerged about Cruz's history before the shooting. CNN obtained a 2016 report from the Florida Department of Children and Families that said Cruz engaged in self-destructive behavior and began cutting his arms after a breakup with a girlfriend.
He also announced plans to buy a gun, put racial slurs and hate symbols on his backpack and suffered from depression, attention deficit hyperactivity disorder and autism, the report said.
DCF spoke with the teen's now-deceased mother, Lynda Cruz, who told them her son began cutting his arms after the breakup and making posts to Snapchat. Previously, Cruz had put a Nazi symbol on his backpack and "had hate signs on a book bag, stating, 'I hate n*****s,'" according to the report.
Despite Cruz's behavior, the report concluded the "final level of risk is low," because the teenager was residing with his mother, receiving in-home mental health services and attending school. His mother died in November after battling the flu and pneumonia.
In a statement Monday, DCF Secretary Mike Carroll said the agency "is absolutely heartbroken and disgusted by last week's tragedy."
Once the department learned the shooter had a history with the agency, Carroll said officials began the process of asking a court to release records of its involvement with Cruz and conducted a review.
"In these investigations, DCF relies on the expertise of mental health professionals and law enforcement and these records show that DCF took the steps to involve these partners in investigating this alleged abuse. Cruz was receiving mental health services before, during, and after our investigation was closed, he was living with his mother, and attending school," Carroll's statement said.
Cruz is being held without bond in Broward County. He appeared in court Monday for a hearing in the sealing of certain documents in the case but didn't speak publicly and looked down most of the time.
Facing charges of premeditated murder, he is willing to plead guilty to avoid the death penalty, according to the public defender's office representing him.