The National 9/11 Memorial & Museum has permanently expanded its annual commemoration ceremony to include seven moments of silence, adding a new tribute for victims of 9/11-related illnesses.
The change, announced ahead of Thursday’s 25th anniversary ceremony in New York, marks the first structural alteration to the ritual since its inception. The seventh pause will honor the thousands who have died from diseases linked to toxic exposure during the aftermath of the 2001 attacks.
“The National September 11 Memorial & Museum leads the nation, and the world, in marking the anniversary of the day that changed our lives forever,” the organization stated in its announcement. The ceremony begins at 8:30 a.m. ET on the Memorial plaza, with the first silence observed at 8:46 a.m., the moment Flight 11 struck the North Tower.
The six traditional pauses acknowledge when each World Trade Center tower was struck and fell, the Pentagon attack, and the crash of Flight 93. The new seventh silence follows the annual reading of victims’ names and will become a permanent fixture in future ceremonies, the Memorial & Museum confirmed.
Michael O’Connell, a former FDNY member, knows the delayed toll of that day intimately. Six years after the attacks, he woke to a body swollen to twice its normal size, covered in blotches, burning with fever.
“My body was swollen probably two times the size of what it was the night before. I had blotches all over my body and high fever. Obviously, something was wrong,” he said. The diagnosis was sarcoidosis, an inflammatory disease that causes granulomas to form in the lungs, lymph nodes, skin, eyes and other organs, according to the Cleveland Clinic.
The illness forced O’Connell into retirement from the fire department. He has since become an advocate for the broader 9/11 community, driven by a pledge that those affected will not be forgotten.
“So everyone affected by that day will not get left behind and those that we lose along the way know that we will NEVER FORGET!!!” he wrote.
The U.S. Centers for Disease Control and Prevention has estimated that roughly 400,000 people were exposed to toxic contaminants, physical injury risks, and severe physical and emotional stress conditions in the attacks’ aftermath. The new moment of silence explicitly recognizes this ongoing casualty count, separate from the 2,977 killed on September 11 itself.
The 25th anniversary ceremony’s expanded format reflects a shift in how the institution frames the attacks’ legacy, incorporating the years-long aftermath as an integral part of the historical record rather than a separate epilogue. The Memorial & Museum’s description of the seven silences now includes “those who lost their lives to 9/11-related illness and injury in the years since” alongside the original attack timestamps.
On the morning of September 11, 2001, nineteen al-Qaeda terrorists hijacked four commercial airliners. American Airlines Flight 11 crashed into the North Tower of the World Trade Center at 8:46 a.m., followed by United Airlines Flight 175 striking the South Tower at 9:03 a.m. American Airlines Flight 77 hit the Pentagon at 9:37 a.m., and United Airlines Flight 93 crashed into a field near Shanksville, Pennsylvania, at 10:03 a.m. After passengers attempted to retake control from hijackers. The South Tower collapsed at 9:59 a.m., the North Tower at 10:28 a.m.
The ceremony’s timing structure has long mirrored these precise moments, with each silence marking a specific catastrophic event in the 102-minute span that reshaped American foreign policy, domestic security, and the Manhattan skyline.
The institution’s decision to make the seventh silence permanent rather than limiting it to the 25th anniversary signals a lasting institutional recognition that the attacks’ death toll continues accumulating decades later.
The 25th anniversary commemoration ceremony takes place Thursday morning at the Memorial plaza in New York.