A jackknifed tractor-trailer blocked southbound Interstate 95 traffic Tuesday morning just north of the Okeechobee Boulevard exit, Florida Highway Patrol authorities said. The crash was reported at about 8 a.m. and by 8:30 a.m. West Palm Beach Fire Rescue crews were working to stop a diesel leak that already spilled fuel over about 70 yards of I-95, said Assistant Chief Brent Bloomfield. The tractor-trailer can hold anywhere from 100 to 150 gallons diesel fuel. “Right now it is about getting the diesel leak stopped and getting the truck moved,” Bloomfield said. The tractor-trailer driver was not injured in the crash, he said. Multiple lanes of traffic were blocked, creating significant backup along the interstate during rush hour.