U.S. troops are staying in the center of the Iraqi capital for a second night, after two other columns made advances on the city. Iraqi troops and paramilitaries put up strong resistance in some parts of Baghdad, but were bombarded by American warplanes and tanks. Two international journalists and one Arabic journalist have been killed and four more injured by American fire in central Baghdad. The fate of Saddam Hussein is uncertain after a U.S. bomber destroyed a residential building where he and his sons may have been meeting. A U.S. Commander said detailed forensic work may be needed to establish whether the Iraqi leader and his sons were among those killed.