The 10th anniversary of the Boston Marathon bombing will be marked with a wreath laying at the finish line to remember those who were killed, a day of community service and an event for the public to gather to reflect on the tragedy. The anniversary Saturday will happen two days before this year’s marathon and marks a decade since two bombs exploded near the finish line of the race, killing three and wounding more than 250 people. The explosions plunged Boston and its suburbs into a week of chaos amid a manhunt for two brothers who carried out the attack.