"Our prayers are with the injured -- so many wounded, some gravely," Obama said. "From their beds, some are surely watching us gather here today. And if you are, know this: As you begin this long journey of recovery, your city is with you. Your commonwealth is with you. Your country is with you. We will all be with you as you learn to stand and walk and, yes, run again. Of that I have no doubt. You will run again. You will run again.”
Afterwards, the president and first lady visited with the wounded and their doctors and nurses at three Boston hospitals. Obama also met with hundreds of first responders and race volunteers at Cathedral High School, praising them for embodying "the best of the American spirit."
Earlier, the president signed an emergency declaration to release federal funds to help Boston recover from the tragedy. More than 60 of the injured remain hospitalized, including a dozen in critical condition. Doctors reported that 15 children and adults had limbs amputated as a result of severe flesh, bone and blood vessel wounds.
Investigators believe the bombs were hidden in black duffel bags or backpacks, and constructed of common household pressure cookers packed with nails, ball bearings and buckshot-like BBs. They said they were detonated by timers or remote devices, causing metal shrapnel to spray spectators.
U.S. security officials said similar bombs have been used in terrorist attacks in India, Nepal, Pakistan and Afghanistan.
Killed in the Boston bombings from the metal projectiles was 8-year-old Martin Richard of Boston. A widely distributed grade school photo of him holding a handmade poster saying, "No more hurting people. Peace," has become an international symbol of the tragedy.
Also killed in the blasts were Krystle Campbell, 29, a restaurant manager in Arlington, Mass., and Lu Lingz, 23, a Chinese national graduate student at Boston University.