Today marks the anniversary of the Boston Marathon bombings.
A total of three people were killed and 260 wounded when two bombs exploded at the finish line.
Brothers Tamerlan and Dzhokar Tsarnaev were charged with planning and orchestrating the attack. Tamerlan died following a shootout with police days after the bombings.
Dzhokhar was found in a backyard boat, and is awaiting trial.
A flag raising ceremony and a moment of silence was held at the finish line.
President Obama observed a moment of silence at 2:49 p.m., the moment the first bomb went off.