The two blasts, 12 seconds apart, rocked the finish line of the Boston Marathon yesterday, killing at least three and wounding 176. // The explosives used in the Boston bombing were made out of 6-liter kitchen pressure cookers, packed with shrapnel and explosives, and hidden in black duffel bags left on the ground near the finish line. // Across the nation, police have tightened security in the aftermath of the Boston bombings. Dave and Luke talk about how what happened in Boston might affect how people approach large, public events in Seattle. // Tom joins Dave and Luke to correct a story about the family of an 8-year-old killed in the bomb blast. The father of the boy is thanking family, friends and strangers for their support following his son's death.