Tasos Katopodis/Getty Images(WASHINGTON) -- Americans advocating for gun reform are taking to the streets in communities across the U.S. Saturday to participate in protests sparked by the back-to-back mass shootings in Uvalde, Texas, and Buffalo, New York. The nationwide marches were organized by March For Our Lives, a group founded by student survivors of the 2018 high school shooting in Parkland, Florida, that killed 17 people. Saturday's marches are in response to the May 24 shooting at a Uvalde elementary school that killed 19 students and two teachers, as well as the May 14 massacre at a Buffalo grocery store where 10 people, all of whom were Black, were gunned down in an alleged hate crime. Jun 11, 3:54 pm 'No one should be able to inflict these types of injuries' At the March For Our Lives rally in Los Angeles, one woman held a sign reading: "Send the guns to Ukraine." Dr. Jeffrey Birnbaum, a pediatric emergency medicine doctor in LA and a Parkland, Florida, native, explained the severity of semi-automatic rifle injuries. He recalled his first experience treating patients shot by semi-automatic rifles, saying "the images of their injuries will be forever burned into my mind." "I vividly remember thinking that no one should be able to inflict these types of injuries on a fellow human being," Birnbaum told the crowd. A survivor of the 2014 mass shooting at the University of California Santa Barbara also shared her experience at the LA rally. She said after the shooting, her mother begged her to drop out of college, terrified for her safety. Last month's Uvalde, Texas, shooting came one day after the anniversary of the UCSB massacre. She said she doesn't want any other generation to endure this grief. "I know that we are exhausted -- but we must continue showing up … because I can't take it anymore," she said. Jun 11, 3:01 pm Buffalo community marches weeks after mass shooting Buffalo, New York, residents held a March For Our Lives rally on Saturday, weeks after a mass shooting that killed 10 shook their community. Another rally was in Parkland, Florida, home to the 2018 school shooting that killed 17. Americans in cities across the nation, from New York to Chicago, also joined in, taking to the streets and making their voices heard. Jun 11, 2:37 pm A teacher's perspective "We need fewer guns in schools -- not more of them!" Randi Weinstein, president of the American Federation of Teachers, said in a passionate speech in Washington, D.C. Teachers want to be teaching, not holstering firearms. We need fewer guns in schools, not more of them. #MarchForOurLives pic.twitter.com/jFzliaJcXR — AFT (@AFTunion) June 11, 2022 "Teachers want to be teaching!" she said. "As we head back to school this fall, please arm us with resources -- with books, with school counselors. Not with bulletproof vests." Weinstein also addressed critical race theory, noting, "If we have the judgment to shoot a bad guy, why don't we have the judgment to plan our lessons?" Jun 11, 2:08 pm MLK's granddaughter returns to stage Yolanda King, a 14-year-old granddaughter of Martin Luther King Jr., returned to the Washington, D.C., March For Our Lives stage, four years after she addressed protesters at age 10. "Like so many of you, I come from a thoughtful, prayerful family. My grandfather was taken from the world by gun violence," the teen said. King stressed that this movement "isn't only about kids -- it's about all of us." "We've had enough of having more guns than people," she said. Our "leaders" care more about getting elected than the lives of children. It's time to change that. Today we will march in Washington, D.C. to demand federal action against gun violence NOW. pic.twitter.com/kOwD0zJQqN — Martin Luther King III (@OfficialMLK3) June 11, 2022 Jun 11, 2:06 pm Crowd briefly disperses in false alarm The Washington, D.C., crowd briefly dispersed in a false alarm incident. Activist Fred Guttenberg, whose 14-year-old daughter Jaime was killed in Parkland, took the mic to calm the protesters, saying everyone was OK and "there is nothing to be concerned about." Speakers then resumed. Jun 11, 1:48 pm Congresswoman shares personal story surviving gun violence Rep. Cori Bush, D-Mo., shared a personal story at the Washington, D.C., march, recounting when, as a young adult, she was in a relationship with an abusive partner who owned guns. "He did not approve of the way I was cooking … we began arguing, he started to hit me. I decided to run out of the apartment," Bush said. "As I ran, I remember thinking to myself, why isn't he chasing me? … When I turned back for a moment … I heard shots. Shots fired. But I didn't know if they were aimed at me. Until they started whizzing past my head." "That moment of horror, it stays with me," Bush said. "It's so deeply traumatic and completely preventable," Bush said, referencing the boyfriend loophole, red flag laws and universal background checks. Bush said, "We will never give up our push to save lives." Jun 11, 1:26 pm Parkland dad, survivor take the stage Manuel Oliver, whose son, 17-year-old, Joaquin was killed in Parkland, said in Washington, D.C., "Our elected officials betrayed us and have avoided the responsibility to end gun violence." He said, "If lawmakers who have the power to keep us safe from gun violence are going to avoid taking action," then he's calling for a nationwide strike of schools, from elementary to college. "Avoid attending school if your leaders fail … to keep us safe," he said. "Avoid going back to school if President Biden fails to open a White House Office of Gun Violence Prevention so that we can finally give this issue the attention that it deserves." Oliver appeared on stage with David Hogg, a Parkland survivor and March For Our Lives co-founder, who vowed, "This time is different." "This is not a political issue -- this is a moral issue," Hogg said. He suggested combatting gun violence the way the U.S. addressed cigarettes. "With cigarettes, we didn't just change the laws -- we addressed why people want to smoke in the first place," Hogg said. "We have to address how people get guns and why they feel the need to pick them up in the first place. We must address the fact that the reason why communities like Parkland don't have shootings on a daily basis isn't because we necessarily have the strongest laws … we have some of the most resources." Jun 11, 1:20 pm NY AG joins Brooklyn march New York Attorney General Letitia James joined a march in Brooklyn, tweeting, "We will fight every single day until we get the common-sense gun reforms this nation needs to end gun violence and save lives." Today, New York joins cities across the nation to #MarchForOurLives and say: Enough waiting. Enough praying. Enough offering empty thoughts. We will fight every single day until we get the common-sense gun reforms this nation needs to end gun violence and save lives. pic.twitter.com/hD0QWItyNq — NY AG James (@NewYorkStateAG) June 11, 2022 #MarchForOurLives getting started over here at Cadman Plaza Park. Activists calling for stricter national gun laws. Crowds set to march across the Brooklyn Bridge. pic.twitter.com/UtpMsJde3u — NYC Mayor's Office (@NYCMayorsOffice) June 11, 2022 Jun 11, 1:04 pm DC mayor: Tell your senators 'make change now-- or get out of our way' Washington, D.C., Mayor Muriel Bowser told protesters she's frustrated because "we have been here before." "We're not asking for a lot. We're asking to drop off our children at school without having to worry that someone will bring an AR-15 into their classroom. We are asking to go to the grocery store without worrying that someone will be shot dead by a gunman who is filled with hate. We are asking to let our children go to the