CCTV with Audio:San Francisco, A preliminary investigation into a crash between two San Francisco Municipal Railway trains over the weekend that sent a dozen people to area hospitals indicates one of the trains was speeding, Muni officials said Tuesday. The crash occurred at about 2 p.m. Saturday at Fourth and King streets, one block south of AT&T Park. According to Muni officials, a one-car, T-Third train going west on King Street between Third and Fourth streets rear-ended a two-car N-Judah train that was stopped at the Fourth Street traffic signal. The back of the N-Judah train was heavily damaged in the crash. "Based on the investigation so far, it appears as though the T-Third train was traveling at 17 mph," Muni spokesman Judson True said Tuesday. He said that section of roadway is a 3-mph zone for Muni trains. Muni is also investigating whether the T-Third operator may have been on a cell phone at the time of the crash. Video footage taken just after the...