STEFANIE DAZIO and JOHN ANTCZAK Associated Press SANTA CLARITA (AP) — A student pulled a gun from his backpack and opened fire at a Southern California high school Thursday, killing two students and wounding three others before shooting himself in the head on his 16th birthday, authorities said. The attacker was hospitalized in critical condition, officials said, and investigators offered no immediate motive. The gunfire began around 7:30 a.m. at Saugus High School in the Los Angeles suburb of Santa Clarita. Authorities estimated that the suspect took just 16 seconds to pull out the weapon, shoot five classmates and turn the gun on himself. At the time, students were “milling around” and greeting each other in an outdoor quad area, sheriff’s homicide Capt. Kent Wegener said.