Shot fired into Obama campaign office in Denver

DENVER - A gunshot was fired into US President Barack Obama's downtown Denver re-election headquarters on Friday while campaign workers were inside but no one was struck, police said.Denver Police Detective Raquel Lopez said a worker inside the office called police in mid-afternoon to report that a bullet had shattered a window pane."Right now, no one is in custody and investigators are looking at surveillance video to see if a vehicle can be identified," Lopez said.Lopez said it was a single shot and no one inside was physically injured.Detectives are not aware of any threats made to the campaign, but are exploring all possibilities, she said.