9/11: A chronological timeline of all major attacks in US post-WTC tragedy

On September 11, 2001, the US and the world were shaken as Al-Qaeda orchestrated coordinated attacks in New York’s Manhattan that forever altered the nation’s trajectory. Four commercial airliners were hijacked, two were flown into the Twin Towers of the World Trade Center, one hit the Pentagon, and the fourth crashed in Pennsylvania after passengers resisted the hijackers. The devastation claimed nearly 3,000 lives and triggered sweeping changes in the United States’ national security, intelligence, and foreign policy, birthing the “Global War on Terror” and ushering in the Homeland Security era.

Since 9/11, multiple attacks have occurred on American soil. While none came close in scale to the WTC tragedy, they have had significant human, emotional, and political impacts. Here is a chronological timeline of major attacks from 2009 onwards in the US.

2009 – Fort Hood shooting 

On November 5, 2009, US Army Major Nidal Hasan opened fire at the Soldier Readiness Processing Center in Fort Hood, Texas, killing 13 people and injuring more than 30.

The attack was initially classified as workplace violence, though later investigations linked his actions to extremist ideology.

2012 – Newtown school shooting

On December 14, 2012, 20-year-old Adam Lanza fatally shot 20 children and 6 adults at Sandy Hook Elementary School in Newtown, Connecticut, before taking his own life. The massacre shocked the nation and reignited debates on gun control and school safety.

2013 – Boston Marathon bombing

On April 15, 2013, brothers Tamerlan and Dzhokhar Tsarnaev detonated two pressure-cooker bombs near the Boston Marathon finish line, resulting in 3 deaths and over 260 injuries. The incident led to a dramatic manhunt, culminating in the death of Tamerlan and the capture of Dzhokhar.

2013 – Washington Navy Yard shooting (DC)

On September 16, 2013, a gunman, Aaron Alexis, opened fire at the Washington Navy Yard, killing 12 people and injuring several others. The shooting was one of the deadliest attacks on a U.S. military installation since Fort Hood.

2015 – San Bernardino attack

On December 2, 2015, a married couple inspired by extremist ideology attacked a workplace holiday party in San Bernardino. Fourteen people were killed, and many were injured. The couple had ties to radical Islamist ideology, and the incident heightened awareness around lone-actor terrorism.

2016 – Orlando Pulse nightclub shooting

On June 12, 2016, Omar Mateen killed 49 people and wounded 53 others in a mass shooting at Pulse, a gay nightclub in Orlando — making it one of the deadliest attacks since 9/11. Mateen pledged allegiance to ISIS during the attack, which was investigated as a terrorist act.

2017 – Las Vegas mass shooting

On October 1, 2017, a lone gunman, Stephen Paddock, opened fire from a hotel window at the Route 91 Harvest Festival, killing at least 50 and injuring more than 200. The shooter’s motive remains unknown, and the scale marked a grim new chapter in the U.S. mass shootings toll.

2017 – Sutherland Springs church shooting (Texas)

On November 5, 2017, a gunman opened fire inside the First Baptist Church in Sutherland Springs, Texas, killing 26 worshippers and injuring 21 others. It was the deadliest mass shooting in a place of worship in US history.

2018 – Parkland school shooting

On February 14, 2018, a gunman opened fire at Marjory Stoneman Douglas High School in Parkland, Florida, killing 17 people and injuring 17 more. It became one of the deadliest school shootings in US history and sparked a nationwide youth-led movement advocating for stronger gun control.

2025 – New Orleans truck and shooting attack

On January 1, 2025, a pickup truck attack coupled with a shooting on Bourbon Street killed 14 civilians and injured 57, including police officers. Investigators linked the attack to ISIS-inspired motives.

Several pipe bombs were found in the vehicle, making it one of the deadliest attacks since 9/11.