boston marathon victims

Boston honors marathon bombing victims

NBC News: A year after two explosions and the events after killed 4 and injured more than 260 in Boston, mourners gathered at the bombing sites to remember the victims and give thanks to the first responders and average citizens who aided rescue efforts.

A memorial service is being held nearby, with Vice President Joe Biden in attendance.

After the service, attendees and others will gather at the Boston Marathon finish line for a moment of silence at 2:49 pm ET, the exact moment the explosions occurred.

Watch live video and see more updates at Breaking News.

Photo: A Boston firehouse that lost two of its own in a fire last month pay tribute to the marathon victims on April 15. (Jim Seida/NBC News)