A woman and her unborn child were killed in a weather-related car crash on a Mississippi highway Wednesday.

Officials with the Chickasaw County Sheriff’s Office report that the fatal wreck occurred Wednesday afternoon when the vehicle the woman was driving slipped off the road and hit a tree.

The wreck occurred on Highway 15 south of Houston.

The woman and her unborn child are the third and fourth winter-related deaths reported since Saturday by the Mississippi Emergency Management Agency.

The identity of the woman has not been released.