Boston Marathon bombing: Tribute held to mark 1-year anniversary

BOSTON (KABC) -- One year after explosions ripped through Boston during the city's marathon, thousands pour in to pay their respects for the anniversary.

The first tribute of Tuesday began with a wreath-laying ceremony dedicated to the three people who died, more than 260 people who were injured and the first responders, doctors and nurses who helped them.

Families of the bombing victims - Martin Richard, Krystle Campbell and Lu Lingzi - and of Massachusetts Institute of Technology police Officer Sean Collier, who was killed in the aftermath of the blasts, attended the ceremony.

"These terrorist acts that keep happening, we need to rise above them and prove that we're resilient and we're strong and that we can create something good out of something so awful," said Sally Duval, a Boston Marathon runner.

Vice President Joe Biden, Gov. Deval Patrick and former Mayor Tom Menino will be among the dignitaries expected to honor the victims later Tuesday during a program at the Hynes Convention Center. Survivors of the bombing will also speak.

Between 2:30 p.m. and 3 p.m., a moment of silence is expected to be held at the marathon finish line marking the time and place the two bombs exploded. A flag will then be raised and church bells will ring across the city.

People around the country are also paying their respects. A group of runners raced in a month-long relay from Los Angeles to Boston to raise money for the wounded. The runners traveled 10-to-20 miles, then passed the baton to runners in another city.

Authorities allege brothers Tamerlan Tsarnaev, 26, and Dzhokhar Tsarnaev, who was 19 at the time of the bombings, were responsible for the attack. The former died in a shootout with police four days after the attack, while the latter was captured and is being detained pending trial.

Dzhokhar Tsarnaev pleaded not guilty to 30 federal charges, including using a weapon of mass destruction. His trial is set to begin in November.

The 118th Boston Marathon is scheduled for next Monday.

The Associated Press contributed to this report.