RIVERSIDE, Calif.—Mourners in California said prayers and their final goodbyes Saturday to three Marines killed in last month’s bombing in Afghanistan. Family and friends of Lance Cpl. Kareem Nikoui packed a church in Riverside to celebrate the life of the 20-year-old Marine from Norco. He was one of 13 U.S. troops killed in a horrific suicide bombing at Afghanistan’s Kabul airport, which also claimed the lives of more than 160 Afghans, on Aug. 26. Nikoui sent videos to his family hours before he died, showing himself interacting with children in Afghanistan. Phil Wozniak, pastor of Grace Fellowship Church Norco, said Nikoui pulled three families to safety and went back to the airport to rescue a child when the bomb went off. “It didn’t surprise me that those were his last moments,” his sister Shyler Chappell said. She said her brother had wanted to become a Marine “for as long as …