A Napoleonville woman was killed Monday after her car crashed into a ditch in a one-vehicle accident, State Police said.

Thelma Rainey, 63, was driving south on La. 403 in Assumption Parish, coming out of a left curve in the road when for unknown reasons she turned her vehicle, a 1996 Grand Marquis, sharply to the right, according to a State Police news release.

Her car overturned in a ditch and Rainey, who was not properly restrained, was thrown from the vehicle, the State Police said. She was pronounced dead at the scene by the Assumption Parish Coroner’s office, according to the report.

There were no other occupants in the car, State Police said.

Impairment is suspected to be a factor in the crash, which remains under investigation, and routine toxicology tests are pending, State Police said.