Barack Obama to lead US in 9/11 memorials

WASHINGTON — President Barack Obama is joining the nation in remembering the nearly 3,000 people who died in the Sept. 11 attacks 15 years ago.

Obama is observing the somber anniversary with a moment of silence in the White House residence at 8:46 a.m. ET. That’s when the first of four hijacked airplanes slammed into the north tower of New York City’s World Trade Center on Sept. 11, 2001.

WATCH: 15 years ago, the deadliest terrorist attack on U.S. soil took place. Take a look back at the timeline of tragic events that unfolded on that day.

2:43 9/11: The timeline of a tragedy

Afterward, Obama will address a Pentagon memorial service.

READ MORE: Toronto air traffic controller recalls ‘eerie’ events of 9/11 15 years later

Nearly 3,000 people were killed in New York, Pennsylvania and at the Pentagon when al-Qaida terrorists crashed the airplanes in those locations.

U.S. forces killed al-Qaida leader Osama bin Laden nearly a decade later during a May 2011 raid that Obama authorized on his Pakistani hideout.