After the crash, Huang’s brother said Huang had talked about the car swerving toward the highway barrier. Huang supposedly complained to the Tesla dealership but said that they could not replicate the issue. Tesla previously confirmed that Autopilot was engaged at the time of the crash. The company has insisted that Huang was at fault, saying that the driver received several “hands-on warnings” and that the only way the crash could have happened was if Huang wasn’t paying attention.

Huang’s family has sued Tesla, alleging that the Model X was “defective” in its design, and a preliminary investigation report by NTSB found that the vehicle sped up just before hitting the road barrier. The report also said the driver’s hands were not detected on the steering wheel in the six seconds before the crash.

Engadget has reached out to Tesla for comment.

BREAKING NEWS: Tesla hit with lawsuit by family of Walter Huang, Apple Engineer who died last year when autopilot in Model X steered him into a traffic barrier Southbound 101 in Mountain View. #ABC7now pic.twitter.com/1cEql1vllc

— Dan Noyes (@dannoyes) May 1, 2019

At the time, Tesla CEO Elon Musk published a blog post about the crash and revealed that “The driver had received several visual and one audible hands-on warning earlier in the drive and the driver’s hands were not detected on the wheel for six seconds prior to the collision.” He also claimed Autopilot “unequivocally makes the world safer for the vehicle occupants, pedestrians and cyclists,” and said the company was working with investigators to understand what happened. Huang’s family members tell reporters that he’d mention how his vehicle would swerve toward the barrier while on Autopilot, and last year his brother said Huang complained to the Tesla dealership about it.

When the Model X hit the barrier, the crash was particularly severe because a “crash attenuator” that would normally be there to reduce the force of the impact was missing due to a prior accident. All of this information has been noted in a preliminary report by the NTSB about the crash, however it hasn’t been updated since last year. The report also notes that the car accelerated in the seconds prior to the crash, hitting the unprotected barrier at 70 MPH, breaching its battery and catching on fire.

Since the crash, Tesla updated its software reminding drivers to touch the wheel more often and, ideally, remain attentive even with Autopilot enabled. It has continued to develop the Autopilot tech and promise a Full Self-Driving package, that works using radar and cameras without adding object-detecting LiDAR technology that Musk called “expensive and unnecessary.” According to the CEO, Full Self-Driving will be available this year from Tesla with self-driving taxis by 2020 and, eventually, cars without a steering wheel or pedal.