BEAUFORT, S.C.—Two Marines were able to eject and walk away alive when their fighter jet crashed on the family plantation of South Carolina’s former governor. The F/A-18D Hornet was on a routine flight over the Beaufort, South Carolina area, on Thursday afternoon, Marine Corp Air Station Beaufort said in a statement. At the crash site, there was smoke coming from the aircraft and a brushfire, military officials said. Former South Carolina Gov. Mark Sanford said the jet crashed near where his late father is buried on Coosaw Plantation, which is the family’s property. Sanford and his siblings grew up there, he told The Charlotte Observer. Sanford’s sister, Sarah Sanford Rauch, saw the jet’s engine catch fire and turn nose-down toward the ground, she said. “I said to my brother, ‘No, no, no, this is bad,’ ” Rauch told The Post and Courier. “And then about a second later there was …