A missing South Carolina woman has been found dead.

Shelia Thompson, of Greenville, was last seen on the evening of Monday, Dec. 2, and was reported missing by her family a day later on Tuesday, Dec. 3, the Greenville County Sheriff’s Office said in a news release.

According to the sheriff’s office, Thompson, 54, was reported as having “serious medical conditions,” although her specific medical history was not made available.

Around 10:45 p.m. local time on Sunday, Dec. 8, the Anderson County Sheriff’s Office responded to a call that a vehicle had been found submerged near West Church Road and Alpen Road in Easley, Fox affiliate, WHNS reported.

The Greenville County Sheriff’s Office later confirmed on social media that she was “found deceased” in the car.

According to the Anderson County Coroner’s Office, the 54-year-old’s drowning death has been ruled accidental, reported WHNS, NBC affiliate WYFF and CBS affiliate WSPA.

The corner said that it appeared Thompson lost control of her car while driving on West Church Road, then traveled off the road and into the creek, according to the outlets.

Representatives from the Anderson County Coroner’s Office and the Greenville County Sheriff’s Office did not immediately respond to PEOPLE’s request for comment.

At the time the car was discovered, Thompson’s family was also searching the area after learning that her cellphone “pinged” in the vicinity, reported WYFF.

“My sister is the sweetest person you would want to know,” sister Toni Fuller told WHNS in a statement. “She has 4 loving children, 7 grands, she was very spiritual and loving. She is the glue that holds the family together and she is already missed by the entire family.”

An investigation into Thompson’s death is currently ongoing by both the Anderson County Coroner’s Office and the South Carolina Highway Patrol.