BOSTON - A pressure cooker stuffed with gunpowder and shrapnel caused at least one of the blasts at the Boston Marathon that killed three people and injured 176 others in the worst attack on US soil since Sept. 11, 2001, law enforcement sources said on Tuesday.
US President Barack Obama called the two bombings on the marathon finish line an "act of terror" and police said parts of the center of Boston could be closed for days as they investigated the blasts that caused several people to lose limbs.
"When these kids came in ... they were just so badly hurt, just covered with singed hair and in so much pain, it was just gut-wrenching," said David Mooney, the director of the trauma program at Boston Children's Hospital. "Pulling nails out of a little girl's flesh is just awful."
At least 10 people had limbs amputated as a result of their injuries, officials at hospitals said.