FORT WORTH — About a dozen passengers walked on the ties of two tiny trestles after a Forest Park Miniature Railroad locomotive broke down Saturday.“There were some old people trying to cross that bridge,” said passenger Mike Tidwell, 56 of Roanoke. “The spaces between the ties were about eight inches. Somebody could have really got hurt.”There were no injuries. But Tidwell said there were about 100 riders on the train when it broke down on a trestle that crosses the Trinity River. The passengers had no choice but to walk on the ties to get off the bridge. But then several walked about a quarter mile from there to the station, crossing a second, smaller trestle. The train runs between that station near the Fort Worth Zoo and another in Trinity Park.John Morse, who said he has been an engineer on the train for 10 years, said there may have been some misunderstanding when he asked everyone to stay in a field near the tracks until he could get back with another train to take them to the station.“As people were coming off the train and walking off the bridge, I told them to wait there and not to cross the other bridge,” Morse said. “I said that at least three times.”As he returned with the rescue train, Morse said he had to stop because about a dozen passengers were walking across the second trestle.The incident prompted Mike Miller, the miniature railroad manager, to devise an operations policy change to ensure that a train employee will stay with riders during future breakdowns.“We’re always in radio communications, and [Morse] told me that he was walking back to get the other train,” Miller said. “He told me that he asked the passengers to stay where they were until he got back with the other train. From now on, someone will stay with the passengers until we get them back to the station.”The 5-mile miniature train ride has been a mainstay Fort Worth attraction for more than 54 years.