The new tribute will honour first responders and survivors who died from illnesses linked to toxic exposure following the September 11, 2001, attacks.

New York City’s annual September 11 commemoration at Ground Zero will feature a seventh moment of silence this year to honour first responders and survivors who have died from illnesses linked to exposure to toxic dust and debris following the 2001 terrorist attacks.

The additional moment of silence will come alongside the traditional six observed during the ceremony, which mark the four plane crashes and the collapses of the World Trade Center’s Twin Towers.

According to the 9/11 Memorial & Museum, a seventh bell will be rung during this year’s ceremony to recognise those who have died from illnesses associated with the aftermath of the attacks.

The change comes as the United States approaches the 25th anniversary of September 11, while the long-term health consequences of the attacks continue to claim lives.

New York Mayor Zohran Mamdani said more people have now died from 9/11-related illnesses than were killed on the day of the attacks, when nearly 3,000 people lost their lives.

More than 57,000 people enrolled in the World Trade Center Health Program have been diagnosed with cancer, while nearly 7,000 enrolled responders and survivors had died as of March 2024.

The federal programme provides medical monitoring and treatment for illnesses associated with exposure to the toxic environment at Ground Zero. It also covers eligible responders and survivors connected to the attacks at the Pentagon and near Shanksville, Pennsylvania.

The latest commemoration comes just days after New York City released more than 170,000 pages of previously undisclosed records indicating that officials at the time knew the air around Ground Zero was unsafe, despite public assurances that it was safe to breathe.

For survivors and families of deceased first responders, the additional tribute represents recognition of people whose lives were affected or lost years after the attacks.

The seventh moment of silence is expected to underscore the continuing human cost of September 11, as survivors and first responders continue to face cancer, respiratory illnesses and other health conditions associated with their exposure to the toxic environment following the attacks.

The September 11 attacks remain one of the darkest moments in modern American history. On September 11, 2001, hijackers seized four commercial aircraft, crashing two into the World Trade Center in New York, one into the Pentagon and another into a field near Shanksville, Pennsylvania.