An investigation is underway after a Washington state woman spent nine days at a car tow lot after her mother parked the vehicle she was riding in at a gas station and walked away, authorities said.

The unidentified woman, who was described by police as being severely disabled, was discovered inside the car shortly after her sister reported her missing to police on Feb. 14. She was taken to a hospital in serious condition, the Kent Police Department said Tuesday.

“We are extremely relieved that we were able to locate and rescue the victim,” Kent Police Chief Rafael Padilla said in a statement announcing her recovery. “If not for the efforts of our Officers and the support of King County Sheriffs and Fire, this incident would likely have ended in tragedy.”

Authorities said the woman was last seen on Feb. 5 when her mother, who police identified only as a 45-year-old Kent resident, parked her car at a Kent gas station and then walked away, leaving her adult daughter inside the car amid near-freezing conditions. The gas station contacted a towing company to remove the vehicle, apparently not knowing someone was inside.

“The property owners knocked on the car window, doors were locked,” Bonafacio Pauza, who owns the towing company that moved the vehicle, told Seattle station Q13 News. “When my driver got there, he did the same thing. No one responded.”

Pauza said it wasn’t until police contacted his company, asking them to search the vehicle, that the door’s lock was broken and the woman was found in the backseat covered by clothing and other debris.

“You don’t expect to find, especially after a car that’s been impounded for a few days, that there’s actually someone still inside it,” he told King 5 News. “She was bad enough that the employee immediately contacted 911 and had the ambulance and the police dispatched out here.”

An investigation is underway, police said in a statement.

Authorities did not immediately respond to HuffPost’s requests for comment Thursday.