(Reuters] – A father of a Florida high school student who died in the Parkland shootings marked the fourth anniversary on Monday. He climbed a crane to the White House, and demanded that the Biden administration address gun violence.

Manuel Oliver, gun-control advocate and author, unfurled an inscription that said “45K people killed from gun violence on their watch”, above Joaquin Oliver’s photograph. This was the most violent high school shooting incident in American history, with 17 victims killed at Marjory Stoneman Douglas High in Parkland.

Joaquin will be heard by the entire world today. Oliver shared a message that is very important in the video he uploaded to Twitter (NYSE) while wearing safety gear and a helmet from the top of the crane, which was 150ft (46m), as officers below watched.

Oliver said that he still has not been able to meet with President Joe Biden.

Biden stated Monday in a statement that his administration is working to curb gun crime. This includes reducing the amount of untraceable firearms, cracking down against gun dealers who break the law, and encouraging safe firearm storage.

He stated, “As Parkland remembers those who were killed there, we also stand by Americans across the nation who have been affected by gun violence or whose lives have been forever changed because of a shooting.”

Nikolas Cruz (the accused shooter) was a former student expelled from Parkland. On February 14, 2018, he opened fire inside the South Florida high-school with an AR-15-style rifle and killed 14 students, three school staff members, and injured 17 more.

Cruz pleaded guilty on October 17 to 17 murders and 17 attempts murders. The jury will determine if Cruz faces death or is sentenced to life imprisonment without parole.

Oliver joined many Parkland families and has become an advocate against gun violence, calling for federal legislation to end the problem. In honor of Oliver, the 54-year old artist also traveled around the United States to create “Walls of Demand” murals.

Nancy Pelosi, Speaker of the U.S House of Representatives stated in a statement that, “As you mark this day of solemn remembrance and every day thereafter, let us renew and strengthen our commitment to ending gun violence and restoring safety for our schools and workplaces,”