In the weeks following the 9/11 attacks, Special Agents Steven Carr, William Craig, Jerry Jobe, Robert Roth, Gerard Senatore, Paul Wilson, and Wesley Yoo were among the FBI personnel who recovered the deceased and gathered critical evidence in the largest investigation in FBI history. After scientists confirmed a connection between 9/11 responders and their illnesses, the agents—who passed away between 2007 and 2015—were added to the FBI’s Hall of Honor this week. They ranged in age from 44 to 68 at the time of their deaths.

During a memorial service on May 17 at FBI Headquarters for all agents who have died in the line of duty, FBI Acting Director Andrew McCabe called the fallen 9/11 responders “peacemakers dedicated to protecting the lives of Americans.”

“They did their jobs not knowing that responding to the scene of a tragic attack would set into motion another tragedy that they would not realize until many years later,” he said.

In 1962, President John F. Kennedy designated May 15 as Peace Officers Memorial Day and the week in which it falls as National Police Week. Multiple events are held in the nation’s capital each year in the days leading up to and during the week, including a candlelight vigil, a Blue Mass at St. Patrick’s Catholic Church, a wreath-laying ceremony at the National Law Enforcement Officers Memorial, and several others.

This year’s events were underscored by the release of a preliminary FBI report that shows 66 law enforcement officers were feloniously killed last year in the line of duty. An additional 52 officers were killed in line-of-duty accidents, according to preliminary statistics compiled by the Bureau’s Uniform Crime Reporting Program, which will release a full report, Law Enforcement Officers Killed and Assaulted, 2016, in the fall.