Police said a car bomb triggered in the heart of Baghdad on Thursday killed 17 people, sending up plumes of thick black smoke above the central part of the Iraqi capital. A police captain on the scene, speaking on condition of anonymity, said that the blast had narrowly missed a U.S. convoy that passed by seconds before. The explosion gouged a giant crater near Nasser Square on Saadoun Street, a densely populated commercial area with major hotels housing foreigners.