The anniversary of the Boston Marathon bombings promises to be a day of tributes to the three people who died, the more than 260 people who were hurt, and the first responders, doctors and nurses who helped them.
Vice President Joe Biden, Massachusetts Gov Deval Patrick and former Boston Mayor Tom Menino will be among the dignitaries expected to honour the victims today during a programme at the Hynes Convention Centre.
Speakers at the event also will include survivors of the bombing.
Between 2:30 pm and 3 pm (local time), a flag-raising ceremony and moment of silence will be held at the marathon finish line, to mark the time and place where two bombs exploded on April 15, 2013.
Authorities say two brothers planned and orchestrated the attack and later shot and killed a Massachusetts Institute of Technology police officer during an attempt to steal his gun.
Tamerlan Tsarnaev, 26, died following a shootout with police several days after the bombings. Dzhokhar Tsarnaev, 20, has pleaded not guilty to 30 federal charges and is awaiting trial. He faces the possibility of the death penalty.
The Tsarnaevs, ethnic Chechens who lived in the former Soviet republic of Kyrgyzstan and the Dagestan region of Russia, settled in Cambridge, outside Boston, more than a decade ago after moving to the US as children with their family.
Prosecutors have said Dzhokhar Tsarnaev left a hand-scrawled confession condemning US actions in Muslim countries on the inside wall of a boat he was found hiding in after being wounded in the police shootout.
