The family of a woman killed after a Tesla, which was operating using “an automated driving assistance system” according to authorities, crashed into her home is suing both the company and the driver of the vehicle.

As reported by Elektrek, a lawsuit was filed in Harris County District Court by Jennifer and Justin Barbour, the daughter and son-in-law of the 76-year-old victim, Martha Avila. It accuses Tesla of a design defect, and the car’s owner, Michael Butler, 44, of negligence.

Butler’s Tesla Model 3 allegedly collided with Avila’s Katy, Texas, home at around 8pm on June 19, at which time she was standing in her front room. She was later pronounced dead after being airlifted to a nearby hospital. Justin Barbour was also inside and suffered multiple injuries.

The driver is said to have been using the Tesla Model 3’s assisted self-driving system in the lead-up to the crash, and the Harris County Sheriff’s Office said he was cooperative, showing no signs of intoxication. The family is blaming both parties for the crash, alleging that the Tesla vehicle failed to accurately detect the end of the street and the oncoming house. They also claim that the vehicle’s systems failed to warn Butler of the danger and said the technology has a “history of known danger.” Avila’s family is seeking more than $1m in damages.

Tesla appears to have conceded that Butler was at one point using its FSD (Full Self-Driving) system, which despite the name still requires an attentive human behind the wheel. However, the company says the driver was ultimately responsible for the crash after assuming control of the vehicle himself.

In a reply to a post on X, Elon Musk said the circumstances of the crash meant that FSD could not have been in use at the time. “Yes, this makes no sense. FSD drives slowly through neighborhood streets and this was a high speed crash!” he wrote.

Ashok Elluswamy, Tesla’s Head of AI, also commented on the post, supporting Musk’s claims Butler was directly operating the car in the events that lead to the fatal crash. “Yup. In this case, the driver manually overrode self-driving by pressing the accelerator all the way to 100% of the accel pedal in this residential area,” he said. “They reached a speed of 73 mph during the crash, and had the accelerator pressed even after the crash.”

According to Elektrek, Butler had previously told Harris County officials that his vehicle had been on Autopilot (the standard Tesla self-driving system, which is less advanced than FSD) when it collided with Avila’s two-story home. According to ABC, no criminal charges have been filed and the crash is currently under investigation. 

This isn’t the first time that Tesla’s autonomous driving tech has been the subject of legal action involving the National Highway Traffic Safety Administration, which is launching its own investigation into the recent Texas tragedy. Last year, the federal agency opened an investigation into how Tesla reports crashes involving its driver assistance systems, and more recently, a judge ordered Tesla to pay $243 million for a deadly crash dating back to 2019, in which Autopilot was involved.