Jan 29 04:25 PM US/Eastern (AP) - The Florida Highway Patrol says 10 people have died in a series of early-morning crashes on a dark highway that was shrouded in haze and smoke. Officials say at least 18 were injured in crashes on both sides of Interstate 75 south of Gainesville shortly before 4 a.m. Sunday. Authorities are trying to determine what caused the pileup. The highway had been closed for a time because of the mixture of fog and heavy smoke from a brush fire that may have been intentionally set. At least five cars and six tractor-trailers were involved. Dr. Timothy Flynn, chief medical officer for Shands Healthcare, says three of the six patients being treated in the trauma center needed surgery.