ORLAND, Calif. — It was a busload of opportunity: young, low-income, motivated students, destined to become the first in their families to go to college, journeying from the concrete sprawl of Los Angeles to a remote redwood campus 650 miles north.
Those dreams shattered for some Thursday in an explosive freeway collision that left 10 dead — students, chaperones, and both drivers — and dozens hospitalized.
Desperate families awaited word about loved ones Friday, while investigators tried to figure out why a FedEx big rig swerved across the grassy divide of California’s key artery before sideswiping a car and slamming into the tour bus, which burst into flames.
The Serrato family, whose identical twin 17-year-old daughters set off on the adventure on separate buses Thursday, had a panicked, sleepless night. Marisol made it to their destination, Humboldt State University, but there was no word from Marisa, who had been aboard the now-gutted bus.
Friday morning when a sheriff’s deputy asked for Marisa’s dental records, a grim request made to several families, her brother Miguel Serrato, 23, said his family was ‘‘getting a little bit scared.’’ His mother booked a flight north.
Humboldt alumni Michael Myvett, 29, and his fiancee, Mattison Haywood, who were chaperoning, also were killed. Myvett was a therapist at an autism treatment center. Myvett’s manager Kyle Farris said he was ‘‘extraordinary,’’ and that he connected with the children ‘‘on a level few others could, and he contributed to their well-being in such a positive and profound way.’’
‘‘He will be greatly missed,’’ Farris said.
A Facebook photo shows Haywood flashing a diamond engagement ring and kissing Myvett in December near the Louvre Museum in Paris.
The bus was among three Humboldt had chartered as part of its two-day Preview Plus program to bring prospective students to tour the Arcata campus, according to university officials. Before launching the event Friday, university vice president Peg Blake’s voice broke as she asked a crowded theater for a moment of silence in honor of everyone affected by the accident.
Most survivors were injured, some with critical burns or broken limbs. Those who made it out said they scrambled through a kicked-out window. One man, apparently an admissions counselor, was in flames and later died. Those who could sprinted, others staggered, in a desperate dash to the opposite side of Interstate 5 before the vehicle exploded.
‘‘We knew we were in major trouble,’’ said Steven Clavijo, a high school senior from Santa Clarita, who was trying to nap when he felt the bus shake before a loud boom.
After he escaped, two more explosions followed. Clavijo and other survivors watched helplessly, knowing their peers were trapped in the inferno.
Explosions of orange flames engulfed both vehicles, and clouds of black smoke billowed into the sky until firefighters doused the fire, leaving behind scorched black hulks of metal. Bodies were draped in blankets inside the burned-out bus.
‘‘I can only imagine the excitement of these high school students as they were on their way to visit a college campus, and the pride of the adults who were accompanying them,’’ said US Secretary of Education Arne Duncan in a statement. ‘‘Our young people are our greatest treasure, and this loss is heartbreaking.’’
Both drivers were killed, along with three adult chaperones and five teenage students, according to the California Highway Patrol, which reached the scene shortly after the 5:30 p.m. accident about 100 miles north of Sacramento.
Humboldt admissions counselor Arthur Arzola, 26, who recruited in the Los Angeles area, was among the dead. His passion for bringing kids to the university was evident on his ‘‘Meet the Counselors’’ Web page: Humboldt ‘‘provides all students on campus with incredible opportunities that change the world for the better.’’
The 44 teenagers aboard, from dozens of different Southern California high schools, were participating in a program that invites prospective low-income or first-generation college students to visit Humboldt. They were supposed to join hundreds more potential students from across California and the West for a long weekend, paired with existing students and staying in the dorms.
A first bus rolled up to the rural campus at 6:30 p.m. Thursday, and a second arrived after 9 p.m. Word began trickling in to the high schoolers as panicked parents called them.
The bus was operated by Silverado Stages Inc., which is based in San Luis Obispo. Chief executive Michael Vodarsik said only that the company was ‘‘working closely with authorities’’ and trying to support the passengers and families.
The CHP and the National Transportation Safety Board are investigating.