A US Congresswoman is struggling for her life at an Arizona hospital following a shooting incident at a public event in Tuscon that killed at least six persons and injured several others. Democratic Representative Gabrielle Giffords was holding a public meeting at a Safeway grocery store in Tuscon, Arizona, when the incident happened. John Roll, a federal judge from Arizona, is among those killed in the shootout.The incident has sent shock waves across the country. Terming it as an unspeakable tragedy, US President Barack Obama described the incident as a senseless and terrible act of violence that has no place in a free society.Initial media reports said that the lawmaker had died, but later doctors said that she is in critical condition.Law enforcement agencies, later, identified the assailant as Jared Lee Lougher. He reportedly shot the Congresswoman point blank in her head. The assailant attempted to flee, but was overpowered by Giffords' staff and others present at the function.