GREENCASTLE, Pa. (AP) -- A 77-year-old woman is dead after a multi-vehicle accident that shut down Interstate 81 in both directions amid snowy conditions in south-central Pennsylvania. Pennsylvania State Police said Sunday that Beverly Grantier of Wellsville, N.Y., died in the crash at about 10 a.m. Police say a tractor trailer jack-knifed, blocking both northbound lanes and causing vehicles to crash. A total of nine vehicles crashed along the stretch. Grantier was riding in a minivan. Police say another passenger in the minivan, 79-year-old Gordon Grantier, was critically injured. Investigators blamed the sudden onset of snowy conditions. The pileup was at mile marker 6 close to Greencastle, near the Maryland border. Authorities reopened I-81's southbound lanes in the morning and northbound lanes opened after 4:30 p.m.