The most significant incident widely referred to by the phrase "what happened on Patriots Day" in contemporary discourse is the terrorist bombing that occurred during the Boston Marathon on April 15, 2013. Patriots' Day itself is a civic holiday commemorating the opening battles of the American Revolutionary War specifically the Battles of Lexington and Concord and is observed annually on the third Monday of April in Massachusetts, Maine, and Wisconsin. The Boston Marathon traditionally takes place on this holiday, drawing considerable public attention.
On that day in 2013, two homemade pressure cooker bombs detonated approximately 12 seconds apart near the finish line of the 117th Boston Marathon. These improvised explosive devices caused three fatalities, including an eight-year-old boy, and injured an estimated 264 additional individuals, many of whom sustained severe, life-altering injuries such as loss of limbs. The perpetrators, Dzhokhar and Tamerlan Tsarnaev, brothers of Chechen origin, planted the devices amidst spectators. The attack prompted an extensive four-day manhunt, leading to the death of MIT Police Officer Sean Collier, a shootout with law enforcement in Watertown that resulted in Tamerlan Tsarnaev's death, and Dzhokhar Tsarnaev's subsequent capture and conviction.
This tragic event profoundly impacted the city of Boston and the nation, leading to a period of heightened security awareness at large public gatherings and fostering a robust community response epitomized by the phrase "Boston Strong." It underscored vulnerabilities in public event security and prompted widespread discussions regarding domestic terrorism, radicalization, and the balance between public safety and civil liberties. The annual Boston Marathon has since incorporated enhanced security measures, serving as a powerful symbol of resilience.