The ceremonies remembering the one-year anniversary of the Boston marathon bombings began with a wreath-laying ceremony at the site of the explosions.
The ceremony Tuesday morning was attended by families of the three victims who died as well as relatives of a Massachusetts Institute of Technology police officer killed in the blasts' aftermath.
Governor Deval Patrick, Mayor Martin Walsh and Boston Cardinal Sean O'Malley were among those who attended the solemn ceremony held in a light rain. With the music of bagpipes playing, Cardinal O'Malley offered a prayer. It was the first of what promises to be a day of tributes to those who died, the more than 260 people who were injured, and the first responders, doctors and nurses who helped them.
Vice President Joe Biden will be among the dignitaries expected to honor the victims later in the day. President Barack Obama also will observe a moment of silence at the White House at the moment of the blasts.