Thursday, February 7th, 2013 — Seven people were injured Wednesday when a San Francisco cable car carrying about 40 passengers came to a sudden stop in the citys Nob Hill neighborhood, authorities said. One of the injuries to an elderly man who fell and hit his head was considered potentially life-threatening, San Francisco fire spokeswoman Mindy Talmadge told The Associated Press. Four other people were taken to a hospital with non-life-threatening injuries. It appeared a 1.5-inch bolt stuck in the cable cars track caused the sudden stop, San Francisco Municipal Transportation Agency Director John Haley told reporters at the scene.