Two of the planes struck the twin skyscrapers of the World Trade Center in Manhattan’s financial district, while another was flown into the US military headquarters at the Pentagon outside Washington, DC.
The fourth aircraft crashed into a field in Pennsylvania after passengers wrested back control from the hijackers.
Among those killed were 441 first responders, the greatest loss of emergency responders on a single day in the country’s history.
Thousands more were injured, and many still suffer from chronic illnesses, including respiratory diseases, mental health issues and cancer.
“Today my thoughts are with everyone who lost loved ones on 9/11 and with all the people of New York City,” Secretary-General António Guterres said in a post on X.
Ben Saul, Special Rapporteur on counterterrorism and human rights, also paid tribute to the victims, who came from more than 90 countries, their families and loved ones.
He welcomed U.S. efforts to support the survivors, but emphasised that justice remained elusive for many.
“The unfathomable violence on 9/11 against ordinary people going about their daily lives was a crime against humanity, but sadly, 23 years later, the victims remain starved of justice,” he said.
Saul noted that unresolved issues, including prolonged detentions and limited accountability, continue to impact victims and detainees alike, underscoring the need for the U.S. to fully align its counterterrorism policies with international human rights standards.
He urged the U.S. authorities to fully implement the recommendations of his predecessor, Fionnuala D. Ní Aoláin, after her technical visit to the United States and the Guantánamo Detention Facility in Cuba in 2023.
Ní Aoláin made specific recommendations and concluded that the U.S. Government must ensure accountability for all international law violations and victims of terrorism and counter-terrorism.
Appointed by the Geneva-based Human Rights Council, Special Rapporteurs are mandated to monitor and report on human rights situation in country or thematic situations.
They serve in their individual capacity, independent of the United Nations; the mandate holders are not UN staff and do not draw a salary for their work.
