Four former United States presidents, Barack Obama, Joe Biden, George W. Bush, and their wives, attended a ceremony in New York City on Friday morning to commemorate the anniversary of September 11, 2001.
The observance brought together multiple living former presidents and the current president's wife to mark the anniversary of the terrorist attacks that killed nearly 3,000 people.
The 2001 attacks involved hijacked airplanes crashing into the World Trade Center towers in New York, the Pentagon near Washington D.C., and a field in Shanksville, Pennsylvania. The ceremonies held each year serve as a solemn remembrance of the victims and a tribute to the first responders.