PINE GROVE (AP) - Authorities say a woman has been struck and killed by a tractor-trailer on Interstate 81 near the Pine Grove exit.

The woman was walking along the northbound lanes when she was hit Monday night. She was pronounced dead by the Schuylkill County deputy coroner at around 9:45 p.m. Her identity hasn't been made public and it wasn't immediately known why she was walking on the roadway.

Lanes on I-81 were closed for several hours. They reopened around 11 p.m.

State police are investigating.