All northbound lanes of Interstate 270 in Frederick County, Maryland, were closed Wednesday morning after a tractor-trailer overturned near the Dr. Perry Road exit, transportation officials said. The crash was reported shortly before 7:30 a.m., and by 6:40 a.m. authorities had blocked northbound traffic past the interchange while diverting vehicles off the highway. Montgomery County Fire and Rescue Services spokesperson Pete Piringer said the driver suffered minor injuries and was freed from the cab by an off-duty firefighter and a county police officer. Southbound traffic was rerouted to MD-109, with northbound motorists advised to take MD-355 as an alternate route. Officials warned of extended closures and significant delays in both directions while crews worked to clear the wreckage and investigate the cause.