A woman was killed after her motorcycle was struck by a tractor-trailer Wednesday evening, police said. According to State Police Sgt. Lawrence Peele, Raven Barzda, 25, of Newton, was traveling southbound on Route 206 near Halsey Road in Hampton when the tractor-trailer struck her shortly after 5 p.m. She was transported to Newton Medical Center, where she was pronounced dead just after 6 p.m. The name of the tractor-trailer driver has not yet been released. The cause of the accident is unknown at this time and remains under investigation, Peele said.