Last April, an accident involving an unmanned truck occurred in the USA. The car suddenly turned to the left and crashed into a concrete barrier. Fortunately, no one was injured in the incident, but experts are now trying to determine the cause of the accident, reports The Wall Street Journal.

TuSimple – a technology provider for self-driving trucks – blamed human error for the accident. According to his account, “the human in the cockpit did not properly reboot the autonomous driving system before turning it on, resulting in the execution of an outdated command.” The left turn command came in 2.5 minutes ago and should have been erased, but it was not.

At the same time, researchers of self-driving cars say that it is incorrect to blame only humans for road accidents. They said the car’s safety systems were supposed to prevent the maneuver, preventing it from executing a command that was even seconds out of date and making a sharp turn at 65 miles per hour.

TuSimple accepts responsibility and claims that this is the first such incident involving their vehicles.

“While our safety record is many times better than traditional manually-driven trucks, we take our responsibility to find and resolve all safety issues very seriously,” says the company.

The incident is currently being reviewed by the National Highway Traffic Safety Administration. The Federal Motor Carrier Safety Administration, which regulates trucking, also joined the investigation.