An early morning crash on Highway 99 in Butte County left at least three people dead and two recovering from injuries, according to the California Highway Patrol.The wreck happened shortly after 12:30 a.m. Saturday, forcing the closure of Highway 99 between Gridley and Biggs for hours while CHP investigated and road crews cleared crash debris that covered both the north and southbound lanes of the highway.CHP said dense fog in the area at the time of the crash contributed to the pileup of 10 vehicles — five big rigs and five cars.“Fog definitely played a role. It was really low visibility,” said Officer Benjamin Draper of CHP-Oroville. “If someone is driving too fast, and it’s really bad fog, when you can only see as far as ... in front of you, we can get incidents like this.”The collision was so severe, CHP said the exact number of deaths, severity of injuries and full scope of the damage isn't known.“With a crash this bad, there’s a possibility of more coming up as we unfold things or as we pull trailers off of cars,” Draper said.Roadblocks stayed in place much of the day on Highway 99 at Biggs East Highway on the north side to Ord Ranch Road at the south side of the crash scene.CHP Valley Division’s Sacramento-based Multidisciplinary Accident Investigation Team traveled to the crash scene to do the investigation, but with an incident of this magnitude, Draper said it could be months before we know exactly how it happened.Part of CHP’s investigation will involve checking whether any of the vehicles involved captured video of the crash. Draper indicated at least one of the big rigs might have had a dash camera.Officers said the crash serves as an unfortunate reminder that it only takes a moment for road travel to turn deadly.“Anticipate the worst case scenario when you're driving. Especially in heavy fog,” Draper cautioned. “If you can’t see really well in front of you, imagine the person behind can’t see really well (and) the person in front of you can’t see well.”Reducing speed to increase reaction time is a good rule of thumb overall, but in particular, when weather conditions make seeing or stopping a challenge.“There’s no rush that’s gonna be worth it," Draper said. "You will be 100% surprised by what’s in front of you if you do not slow down.”