President Barack Obama has paid tribute at a memorial service in Arizona to the six people killed and 13 injured in Saturday's shooting in Tucson. He said he could not fill the hole torn in US hearts, but urged the nation to honour the victims through unity. He said lawmaker Gabrielle Giffords, who was hurt in the attack, had opened her eyes for the first time that night. Suspected gunman Jared Loughner has been charged with several offences and could face the death penalty if guilty. More than 14,000 people gathered for the service at the University of Arizona's basketball arena, the McKale Memorial Center, in Tucson. There is nothing I can say that will fill the sudden hole torn in your hearts, said Mr Obama. But at a time when our discourse has become so sharply polarized - at a time when we are far too eager to lay the blame for all that ails the world at the feet of those who think differently than we do - it's important for us to pause for a moment and make sure that we are talking with each other in a way that heals, not a way that wounds.
