Tasha Thomas, who was with Crawford when he was fatally shot while carrying a pellet gun at the Ohio store, killed when car struck a pole at high speed

The girlfriend of John Crawford, the young man who was shot dead by police while holding a pellet gun and speaking on his cellphone in an Ohio supermarket last year, has been killed in a car crash.

Tasha Thomas died on New Year’s Day when the car she was travelling in struck a pole in Dayton at high speed and overturned, according to police. The driver, Frederick Bailey, died soon after at a hospital.

John Crawford III shows Crawford, right, with his mother, Tressa Sherrod. Photograph: AP

Thomas, who was 26, was shopping with Crawford at the Walmart in Beavercreek, a Dayton suburb, in August last year when Crawford was shot dead by a police officer. The officer was responding to a 911 call from a customer who said Crawford was pointing a gun at passersby.

Last month the Guardian disclosed that Thomas was aggressively questioned by police after the shooting. A detective accused her of lying, threatened to send her to jail, and suggested that she was high on drugs before telling her that Crawford, 22, was dead.

“It’s just tragic,” Michael Wright, the attorney for Crawford’s family, said on Friday of Thomas’s death. “It is a sad set of circumstances continuing from what happened at Walmart.” Wright, who advised Thomas soon after the shooting, said that her death had been confirmed to him by Anthony VanNoy, Thomas’s attorney. VanNoy could not be reached for comment.

An official in the Montgomery County coroner’s office confirmed that Thomas, who lived in Fairborn, was pronounced dead at the scene of the crash on North Broadway street at 3.06pm and that Bailey, 30, died at the emergency room about 22 minutes later. Police told ABC22 that the car was travelling at between 90 and 100mph.

Surveillance footage released after Crawford’s death showed he was shot after walking around the store with the pellet gun and occasionally swinging it at his side. The shooting was investigated by state officials and handled by a special prosecutor. A grand jury decided in September that the two police officers involved should not face criminal charges.

Crawford’s family last month filed a civil lawsuit over Crawford’s death against the officers, the Beavercreek police department and its chief, and Walmart. All deny wrongdoing.