(CNN) Two Parkland, Florida, parents announced their candidacies Tuesday for the Broward County School Board, running on a platform that no mother or father should ever experience losing a child to a school shooter.

Lori Alhadeff's daughter, Alyssa, and Ryan Petty's daughter, Alaina, were among 17 people killed when a gunman went on a killing spree February 14 at Marjory Stoneman Douglas High School.

Alhadeff, 43, in announcing her bid for the District 4 seat held by Abby Freeman, said that until three months ago she had never imagined herself as a politician or an activist.

"But I never could've envisioned what happened Valentine's Day at Marjory Stoneman Douglas High School in Parkland when my daughter, Alyssa Alhadeff, and 16 others were murdered and so many others injured," said Alhadeff, who has two sons in Broward County Public Schools and who founded the nonprofit, Make Schools Safe

Petty, 48, said his and Alhadeff's worlds flipped that day and they became dedicated to changing a system that allowed the school gunman "to fall through the cracks."

By serving on the school board, he said during a news conference in Fort Lauderdale, "I can represent parents all over the district who deserve to have their children come home to them every afternoon after school."

Parkland shooting victims Alaina Petty, left, and Alyssa Alhadeff.

Standing alongside Alhadeff, Petty announced he will vie for the at-large countywide District 8 seat held by Donna Korn. College student Elijah Manley , 19, has also announced his intention to compete for the seat.

In addition to school safety, Petty and Alhadeff said their priorities will include transparency, accountability and ensuring tax dollars are spent effectively in the classroom.

The day after the deadly rampage, Alhadeff appeared on CNN , taking a break from her 14-year-old daughter's funeral preparations to issue a fiery challenge to President Donald Trump to do something -- anything -- about the epidemic of gun violence in schools.

A mother furiously asks President Trump to "please do something" about guns. She had just made funeral arrangements for her 14-year-old daughter, who was killed in the Florida school shooting. https://t.co/Mrt0Y9124E pic.twitter.com/xn3ODAab1p — CNN (@CNN) February 15, 2018

"How do we allow a gunman to come into our children's school? How do they get through security? What security is there?" she asked. "The gunman -- a crazy person -- just walks right into the school, knocks down the window of my child's door and starts shooting. Shooting her! And killing her!"

The following week, she told NRA and law enforcement officials at a CNN Town Hall that Alyssa, a soccer player, was shot three times during the massacre. She posed a series of questions -- about bulletproof glass, police involvement in schools and on-campus psychologists -- and closed her remarks demanding real solutions: "Enough talk. What is your action?"

Just us and those closest to her. Celebrating the life of Alyssa Alhadeff.#PlayforAlyssa // #ParklandStrong pic.twitter.com/e6m2OFPdtZ — U.S. Soccer WNT (@ussoccer_wnt) March 8, 2018

"I'm still not satisfied with the answers to the questions that I asked back then," she said Tuesday, "and I'm extremely frustrated at the lack of progress that has been made to fix the problems that we all know exist."

Petty, too, took on lawmakers after his 14-year-old daughter was killed. In early March he prodded state legislators who were grappling for consensus on school safety measures by urging them to enhance school security, improve mental health resources for at-risk youth and pass legislation to keep guns away from those who pose a risk to society.

Ryan Petty and Andrew Pollack, fathers of Alaina Petty and Meadow Pollack who both died in the Parkland shooting in attendance for the House Session ahead of the vote for SB7026. pic.twitter.com/POPzqIniYT — Carolyn Sung (@CarolynSungCNN) March 7, 2018

"Our message is simple: We must be the last families to lose loved ones to mass murder in school," he said. "This time must be different and we demand action."

He also voiced his support for Senate Bill 7026, which provided millions for stricter gun control, school security and mental health treatment when Gov. Rick Scott signed it into law in March.

Primary elections for the school board, which presides over the second-largest district in the state, will be held August 28. The general election is slated for November 6.