ELKTON, Md. — Maryland state police are investigating an accident that shut down all southbound lanes of I-95 and left a pedestrian with life-threatening injuries.

Authorities say Sarah Elizabeth Gotfredson of Abingdon stopped her car on the shoulder of the highway in Elkton on Saturday morning. State troopers say she then “entered the highway” for unknown reasons.

Troopers say multiple vehicles managed to avoid her, but Gotfredson was eventually hit by a box truck shortly after walking onto the major highway.

An ambulance took the 32-year-old woman to a hospital with grave injuries. The truck driver was uninjured.

All southbound lanes of I-95 were closed after the morning accident. Traffic was diverted to the right shoulder. Delays stretched back to the state line with Delaware.