When a Georgia woman fell out of a patrol cruiser earlier this month, she slid out of a back door that a deputy forgot to close, according to state investigators.

Brianna Marie Grier, 28, died at Grady Memorial Hospital on Thursday, nearly a week after she fell out of a Hancock County deputy’s moving patrol vehicle.

The GBI released new details about the incident Wednesday, and said in a statement that agents concluded that the two deputies who arrested Grier failed to close the back passenger-side door after they forced the woman into the cruiser.

The preliminary investigation also revealed that the deputies did not put a seat belt on Grier, who was placed in custody with her hands cuffed in front of her.

Deputies arrested Grier at her Sparta home early the morning of July 15. During the ride to the sheriff’s office, she fell out of the patrol vehicle and sustained significant injuries that ultimately proved fatal, according to the GBI’s probe.

Hancock County Sheriff Terrell Primus asked the GBI to take over the investigation the same day.

Grier’s parents told WMAZ-13 they called for help because their daughter was having a schizophrenic episode. They said when the deputies arrived, they handcuffed Grier and put her in the back of the patrol vehicle.

Marvin and Mary Grier told the news station that Primus visited their home after the incident and told them their daughter was trying to escape and managed to kick the door open. But the GBI said early indications show the door was never closed.

Investigators reviewed multiple body camera videos, conducted several mechanical tests on the patrol car and had automotive experts from the Georgia State Patrol test for mechanical malfunctions.

Officials did not release the names of the two Hancock County deputies. According to Wednesday’s statement, they tried to put Grier in the car on the driver’s side, but she refused and said she was going to harm herself. One of the deputies then walked around to the passenger’s side as they struggled to get Grier in the backseat.

The deputy quickly returned to the driver’s side and they managed to get Grier inside the car. They then closed the driver’s-side door.

“The investigation shows that the deputy thought he closed the rear passenger-side door,” the GBI report stated.

He hadn’t. Shortly after driving away from the home, the woman fell out of the vehicle, GBI officials said.