Saddam Hussein was hanged at dawn on Saturday for crimes against humanity, a dramatic, violent end for a leader who brutally ruled Iraq for three decades before he was toppled by a U.S. invasion in 2003. In what looked like a swift response by Sunni insurgents loyal to Saddam, a car bomb killed 36 people in a Shi'ite town -- the sort of sectarian attack that has pitched Iraq towards civil war since U.S. troops broke Saddam's iron grip.