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Two bombs exploded near the finish line of the Boston Marathon on Monday leaving three dead, including an 8-year-old boy, and more than 140 injured. At least 17 people were critically wounded, officials say.
The first explosion occurred around 2:50pm (1850 GMT) on the north side of Boylston Street outside of a Marathon Sports store, causing confusion and panic among runners and spectators. Police and bystanders rushed to help those caught in the first explosion.
A second explosion about 100 yards away tore through the crowd less than 13 seconds later.
Both devices appeared to be unsophisticated and did not include plastic explosives, a federal official involved in the investigation said. The two devices used gunpowder as the explosive and were packed with ball bearings and other shrapnel to maximize injuries, a senior law enforcement official said. Another federal official said that at least one of the devices was detonated in a trash can.
Patients were taken to at least seven hospitals, where at least 140 people were being treated, including eight children. At least 17 patients were in critical condition. Twenty-five more sustained severe injuries.
Many of the patients had sustained injuries to their lower extremities from what looked to be a low-level blast, doctors said.