SAN FERNANDO, Calif.,—San Fernando police asked the public for help locating a 14-year-old girl who disappeared, presumably while on her way to a nearby convenience store. Destiny Isabella Mercado, 14, texted her mother at 1:10 p.m. Saturday for permission to go the 7-Eleven store at Hubbard Street and Borden Avenue, and was believed at her home in the 1900 block of Chivers Street when she sent the message, according to San Fernando police Lt. Irwin Rosenberg. It was not known whether she was on foot when she sent the text, but she apparently did not make it to the store. Mercado’s phone was found at 1:40 p.m. in the area of Hubbard and Glenoaks Boulevard by someone who claimed it was thrown from the right rear passenger seat of a moving vehicle, Rosenberg said. A witness told police the vehicle was a light gray or silver Mazda. It was unknown …