A 3-year-old girl broke her arm in a three-story fall from a Chelsea porch today afternoon, a fire official said. She did not appear to have any other injuries after falling onto the dirt, Chelsea Fire Captain Richard Carroccino said. “I’m a little shocked myself, but there wasn’t a whole lot of traumatic injury that we could see,” he said. The girl climbed onto a weight-lifting bench on the porch, then toppled over the railing, falling about 40 feet, Carroccino said. She was conscious and crying in front of the three-decker home on Chestnut Street with her family when fire officials arrived, Carroccino said. She was taken to Massachusetts General Hospital.Gal Tziperman Lotan can be reached at email@example.com.