SAN FRANCISCO - A tiger escaped its cage at the San Francisco Zoo on Tuesday, killing one person and injuring two others, a newspaper reported. The tiger was shot, San Francisco Fire Department spokesman Lt. Ken Smith told the San Francisco Chronicle. It was not immediately clear how the tiger escaped. The zoo, which had been scheduled to close at 5 p.m. PST, was evacuated. It was unclear whether the victim was a visitor or a zoo worker. Police officers and firefighters are investigating. Officials at first worried that four tigers had escaped, but only one escaped its pen, Smith...