Thousands of students and adults across the U.S. held a moment of silence to honor the 17 people killed one year ago at Marjory Stoneman Douglas High School in Parkland, Florida. /VCG Photo

More than 1,000 Florida schools reportedly paused work at 10:17 a.m. on February 14, to remember the 14 students and three staff members slain last Valentine's Day in the deadliest high school shooting in U.S. history. /VCG Photo

The decision to hold the moment of silence at 10:17 was made in honor of the 17 slain. /VCG Photo

The school massacre on February 14, 2018 inflamed national debate over guns in the states, turned young students and survivors into activists and gave rise to a wave of political demonstrations and a movement led by youth. /VCG Photo