KEY POINTS
• US commemorates victims of the September 11, 2001 attacks 25 years after the tragedy.
• Donald Trump is expected at a memorial service at the Pentagon.
• Nearly 3,000 people were killed after four hijacked passenger planes were used in the attacks.
• Health problems linked to exposure at the attack sites have since claimed more lives, with more than 57,000 cancer cases recorded.
MAIN STORY
The United States is marking 25 years since the September 11, 2001 terrorist attacks, with memorial ceremonies taking place in New York and Washington on Friday.
US President Donald Trump is expected to attend a service at the Pentagon, which was among the targets struck by hijacked aircraft during the attacks.
In New York, relatives of those killed are expected to read out the names of the victims at the site where the World Trade Centre towers once stood.
Nearly 3,000 people died after al Qaeda terrorists hijacked four passenger planes. Two aircraft were flown into the World Trade Centre towers in New York, while another struck the Pentagon, the headquarters of the US Department of Defense.
The fourth aircraft crashed in Pennsylvania after passengers attempted to overpower the hijackers. The intended target of that plane has never been established.
The attacks prompted a massive rescue effort, with thousands of people rushing to the affected areas to search for survivors trapped beneath the rubble.
Friday’s ceremony in New York is expected to include several moments of silence in remembrance of those who died in the attacks and others who later lost their lives from health conditions linked to exposure at the sites.
THE ISSUES
The consequences of the September 11 attacks have extended far beyond the deaths recorded on the day itself.
The US government has acknowledged that deaths linked to illnesses arising from exposure to conditions at the attack sites have now surpassed the number of people killed during the attacks.
The US Centres for Disease Control and Prevention has recorded more than 57,000 cancer cases linked to the attacks.
The collapse of the approximately 400 metre high towers and the fires that followed released dust, glass fibres, asbestos, pulverised concrete, plasterboard, burnt plastics and other pollutants into the atmosphere.
The resulting contamination left the affected areas hazardous for weeks and exposed rescue workers and others at the sites to substances that have been linked to serious health problems.
WHAT’S NEXT
Memorial events will continue on Friday in New York and at the Pentagon as the US commemorates those killed in the attacks and remembers people who later died from related illnesses.
BOTTOM LINE
Twenty five years after September 11, the attacks remain a defining tragedy in the United States, with their impact extending from the nearly 3,000 deaths recorded that day to thousands of subsequent cases of serious illness.
