One Boston Day honors lives lost 13 years after Boston Marathon bombings

Today is One Boston Day, a day for the city to remember the lives lost in the 2013 Boston Marathon bombings and encourage acts of kindness in the community.

Every April 15, the city holds memorial ceremonies to honor the victims, and hosts volunteer events and other service opportunities.

Eight-year-old Martin Richard, 23-year-old Lu Lingzi and 29-year-old Krystle Campbell were killed when two bombs exploded within seconds of each other near the marathon finish line. MIT police officer Sean Collier was shot and killed by the bombers three days later, and Boston Police officer Dennis Simmonds died in 2014 from injuries suffered during a confrontation with the bombers after a manhunt. 

At 10 a.m., Mayor Michelle Wu and Massachusetts Gov. Maura Healey joined the families of the victims to lay wreaths at the memorial site on Boylston Street.

Later in the day there will be a moment of silence at 2:49 p.m. to mark the time of the first explosion, followed by the tolling of bells at Old South Church. 

At noon and 6 p.m., the Stepping Strong Center will host a free, virtual "Stop the Bleed" training to teach people who to respond to a life-threatening bleeding situation. The center is named after bombing survivor Gillian Reny, who nearly lost a leg but was saved by first responders.

Boston City Hall, the UMass Boston Integrated Sciences Complex and other buildings will be lit up in blue and yellow at night to recognize the occasion. 

There's also a One Boston Day cleanup of Franklin Park that will be held Saturday at 9 a.m. You can find more One Boston Day events on the city of Boston website.