Last week on Valentine’s Day, a 19-year-old gunman entered Marjory Stoneman Douglas High School in Parkland, Florida, where he had been expelled. He opened fire just outside the school, and soon began shooting students in hallways and classrooms using an AR-15. Minutes later, 17 students and staff were dead, and 15 others were injured.

We are just a month and a half into 2018, and already the number of school shootings since Dec. 31 has risen into the teens. Predictably, as with every other time innocent Americans have been gunned down in schools, movie theaters, at concerts, or in places of worship, politicians took to social media to offer up “thoughts and prayers” rather than the legislative action we so desperately need.

More than five years ago, my 6-year-old brother Noah was shot and killed in his first-grade classroom in Sandy Hook, Connecticut. Just like those innocent teenagers in Florida, my brother and his classmates and teachers were killed doing exactly what they were supposed to be doing: going to school.

They were murdered in the very place that was supposed to keep them safe, and they were gunned down with a military-style assault weapon that had fallen into the wrong hands. To this very day, it is unfathomable to think that 20 first-graders and six educators could have been senselessly murdered in an elementary school in the United States of America, just 11 days before Christmas.

My brother and his classmates had a right to life. They had a right to safety. My siblings, both of whom were in the school that day as the horror unfolded, had a right to grow up with their brother. All of that was violently torn from them, and these basic human rights have been torn from thousands of other Americans in the years since.

The worst part? Congress has actively chosen to do nothing to keep it from happening again, despite overwhelming evidence from other countries that common-sense gun safety legislation can and does save lives. In the months after Sandy Hook, Congress voted down a measure that would’ve expanded background checks for gun buyers. And since then, thousands more lives have been cut short due to gun violence. More children have been murdered in their classrooms, including in Parkland last week.

I, along with the rest of the country, have seen the cycle play out over and over in the media: News breaks of yet another shooting, politicians offer thoughts and prayers  ― some telling us that these tragedies shouldn’t be politicized or that we shouldn’t have a “knee-jerk reaction” against guns. We are told it’s too soon to talk about gun violence ― when, tragically, it’s much too late ― and then we wait until the next one happens and the cycle begins anew.

Not this time. I can feel that this time is different.

Unlike my brother’s elementary school peers, who were unable to fully grasp what had happened in their school on Dec. 14, 2012, the teenagers from Marjory Stoneman Douglas are speaking out on behalf of themselves and their classmates whose lives were violently cut short. They are giving a voice to the voiceless. And they are demanding change in a way we’ve never seen before. They are calling out politicians who have accepted hefty donations from the National Rifle Association (including the president). They are organizing marches to demand action from American politicians on the gun violence epidemic. They are turning their grief into action so that no more parents, siblings, or friends have to experience the despair and anguish of losing a loved one to senseless gun violence.

Most recently, students from Marjory Stoneman Douglas announced March For Our Lives, a nationwide protest on March 24. According to the website, the march is “created by, inspired by, and led by students across the country who will no longer risk their lives waiting for someone else to take action to stop the epidemic of mass school shooting that has become all too familiar.” Americans are angry, we are fed up, and we have had enough. We are not numb to gun violence, as some have suggested ― in fact, quite the opposite. I am angry as ever, and I am determined.

I recently saw a tweet that suggested that the possibility of passing common-sense gun safety legislation ended as soon as we decided that children dying in their first-grade classrooms was acceptable. Despite having felt this way numerous times in the years since Noah was gunned down at Sandy Hook Elementary, I disagree. Sandy Hook was the turning point. Although we have allowed this to happen far too many times, there is hope. There is too much on the line not to keep fighting. Lives are at stake, and I refuse to allow my brother’s death to have been in vain. Let’s make Parkland the turning point that Sandy Hook should’ve been.

As Emma Gonzalez, a survivor of the school shooting in Parkland, said over the weekend during a rally in Florida: “If all our government and president can do is send ‘thoughts and prayers,’ then it’s time for victims to be the change that we need to see.”

As I watched Emma’s impassioned speech, it hit me more than ever: The future of this country depends on each and every one of us. By voting for politicians who will take action on gun violence, running for office, getting involved with gun violence prevention organizations and mobilizing our communities, we can and will save lives and keep more families from experiencing the heartbreak and trauma that has touched far too many Americans. By standing up and saying “Enough is enough,” we can take our country back.

Let’s join Emma and all of the students from Marjory Stoneman Douglas who are demanding change. Let’s join the mothers who have lost their sons and daughters to senseless gun violence. Let’s join the brothers and sisters who should not have to grow up without their sibling by their side. Let’s stand alongside one another, hand-in-hand, and together be the change that we need to see.

Clarification: Language in this story has been amended to more accurately characterize the weapon used in the Sandy Hook shooting.