The Boston Marathon bombing took place in 2013. On Monday, April 15, two pressure cooker bombs exploded near the finish line in Boston, Massachusetts, killing three people and injuring hundreds. This verified explainer provides a concise timeline, factual context, and key details about the attack, the response, and the ongoing legacy, focusing on what happened and why the date matters. The following sections break down the event chronologically and thematically to support long-term clarity.
Date and Time of the Bombing
When the attack occurred
The bombings happened during the 117th Boston Marathon on April 15, 2013. The first explosion was recorded at approximately 2:49p.m. local time, near the finish line on Boylston Street. A second bomb exploded about 12 seconds later. The attacks occurred near a dense spectator area, maximizing casualties and immediacy of response. No credible prior threat specific to the marathon that day had been reported in official investigations.
Casualties and Immediate Impact
Injuries, fatalities, and initial response
Three people were killed: Martin Richard, age 8; Krystle Campbell, age 29; and Lingzi Lu, age 23. Another 264 people were injured, with at least 17 losing limbs. The initial medical response involved multiple hospitals in the Boston area, including Massachusetts General Hospital and Beth Israel Deaconess Medical Center. The scene was chaotic, with runners and bystanders assisting until professional responders secured the area.
Perpetrators and Manhunt
Identification and pursuit
Two brothers, Dzhokhar Tsarnaev and Tamerlan Tsarnaev, were identified as suspects using surveillance footage and witness evidence. On April 18, 2013, Tamerlan was killed in a shootout with police in Watertown, Massachusetts. Dzhokhar was captured on April 19 after a manhunt that closed a large portion of Watertown and involved thousands of officers. The brothers were motivated by extremist Islamist ideology, according to subsequent investigations and trial proceedings.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Bombing Date | April 15, 2013 | Official investigative reports |
| Casualties (Fatalities) | 3 killed | Law enforcement and court records |
| Injured | Approx. 264 injured | Medical and investigative reports |
| Perpetrators | Dzhokhar and Tamerlan Tsarnaev | Federal indictments and trial transcripts |
| Manhunt Duration | d>April 18–19, 2013 | Law enforcement timelines |
| Tamerlan Tsarnaev Death | April 18, 2013 | Law enforcement reports |
| Dzhokhar Tsarnaev Conviction | April 8, 2015 | Federal court records |
Investigations and Official Findings
Reports and conclusions
The U.S. Department of Justice and the FBI led the investigation, culminating in a detailed final report that outlined the brothers’ movements, motivations, and materials used. Key findings included construction of the devices using fireworks and shrap housed in pressure cookers, remotely detonated with small amounts of gunpowder from fireworks. Plots to attack Times Square in New York a month later were discovered and disrupted, highlighting broader concerns about transnational radicalization.
Legal Proceedings and Sentencing
Trial and conviction details
Dzhokhar Tsarnaev was arrested on April 19, 2013, and charged with using a weapon of mass destruction resulting in death. In April 2015, he was found guilty on all counts. In July 2015, he was sentenced to death for certain counts, though his sentence has faced ongoing appeals. His brother Tamerlan died during the manhunt and was never tried. Several other individuals faced charges for obstructing investigation, including friends who misled authorities about the brothers’ activities.
Community Response and Memorials
Vigils, aid, and lasting tributes
In the immediate aftermath, Boston and the nation rallied in solidarity. Vigils were held across the city and country, and the phrase "Boston Strong" became a symbol of resilience. The One Fund Boston raised over $67 million for victims and families. Annual commemorations and memorials honor the three killed and recognize the hundreds injured. The bombing also spurred policy changes around marathon security and threat assessment nationwide.