Old Lyme — A 31-year-old Middletown woman who had gotten out of her car to check on a child in the back seat was struck and killed by a tractor-trailer Thursday on Interstate 95.

State police identified the woman as Ashley Ferguson of 2 Walnut St., Middletown. The child shared her address.

At 11:28 a.m. police said Ferguson had parked in the right shoulder of I-95 south between exits 71 and 70 in Old Lyme.

Ferguson had exited the Kia Optima she was driving to check the child, seated in a car seat on the driver’s side, when police said a tractor-trailer struck her and the side of the vehicle. Ferguson was pronounced deceased at the scene.

Nicolae Marcu, 47, of Bedford, N.H., was the driver of the tractor-trailer, which is owned by MGR Freight System Inc. of Countryside, Ill.; he was not injured.

Police said Ferguson’s 1-year-old passenger was taken by ambulance to the Shoreline Medical Center but did not sustain any apparent injury. Tammy Vistrand, 44, of Taftville, a passenger in Ferguson’s vehicle, also was not injured.

The crash and the investigation into the crash snarled traffic in the area for much of the day Thursday. Police said the accident remains under investigation and anyone with information is asked to contact state police at Troop F in Westbrook at (860) 399-2100.