Overview
The Boston Marathon bombings occurred on April 15, 2013 during the annual Boston Marathon, an event held each year on Patriots' Day. At 2:49 p.m. Eastern, two improvised explosive devices detonated near the race finish line, thirteen seconds apart. The explosions killed three people and injured many others, causing both physical and psychological trauma and widespread property damage in the nearby commercial district.
Attack details and devices
Investigators determined the explosives were packed into pressure cookers and concealed in backpacks; they were laden with nails and other metal to increase shrapnel injuries. The blasts broke storefront windows, damaged a public library nearby, and scattered debris across the finish area. Bystanders, runners and emergency personnel were immediately involved in rescue and treatment of the wounded.
Response, search and arrest
Local, state and federal agencies conducted a rapid investigation using surveillance footage, witness photos and public tips. Two brothers were soon identified as suspects. A days-long manhunt included a large police presence, a shelter-in-place advisory in parts of the Boston suburbs, and a violent confrontation during which a campus police officer was killed. The older suspect was killed in the confrontation; the younger was captured wounded, charged, and later tried in federal court.
Casualties and medical impact
Three civilians died as a result of the attack, and hundreds were injured. Many victims suffered severe limb and soft-tissue injuries; some required amputations and long-term rehabilitation. Hospitals and trauma teams in the region mobilized to treat mass casualties, and a concerted effort by volunteers and medical staff played a central role in the immediate response.
Investigation, prosecution and public discourse
The bombing prompted extensive forensic and legal proceedings. The surviving suspect was prosecuted in federal court and convicted; sentences and appeals attracted sustained public attention. Authorities reviewed how the devices were constructed and how similar large public events could be protected, leading to changes in security planning and emergency communications.
Aftermath and legacy
The city and nation responded with memorials, benefit efforts for victims and a civic slogan that emphasized resilience. Annual commemorations near the finish line honor those killed and injured and recognize first responders. The incident has been studied in law enforcement, emergency medicine and public-safety fields as an example of coordinated response, community solidarity and the long-term challenges of recovery from an act of terrorism. For more background on the nature of the incident as an act of violent extremism, see terrorist attack.