In a recent blog post, Tesla revealed that the Model S vehicle that was involved in a fatal accident on May 7 in Williston, Florida was in Autopilot mode at the time of the collision. This marks the first known fatality in a Tesla vehicle where Autopilot was active. The National Highway Transportation Safety Administration is currently in the midst of an investigation of the cause of the collision which is believed to include a determination of whether the Autopilot system was working properly at the time of the accident.

According to various news sources, the accident occurred when a tractor trailer drove across a divided highway and in front of the Tesla vehicle. Due to the height of the trailer, the Model S actually passed under the trailer with the initial impact occurring to the vehicle’s windshield. Tesla CEO Elon Musk stated on Twitter that the radar system used by the Autopilot feature did not help in this case because of the height of the trailer. According to Musk, the system “tunes out what looks like an overhead road sign to avoid false breaking events.” Tesla believes that the Autopilot system would have prevented the accident if the impact had occurred to the front or rear of the trailer.

This accident represents the first in what will undoubtedly be many similar accidents that will raise questions regarding the safety of Autopilot systems. Tesla is one of the first automakers to utilize such technology and they have reiterated that they require customers to sign an agreement acknowledging that the system is in a “public beta phase” before they can use it. Some driving experts have criticized Tesla for introducing an Autopilot feature too early believing that the system gives drivers the false impression that the car can handle anything it encounters. By way of contrast, GM has only tested their Autopilot feature privately and Volvo has indicated that they intend to take full liability for their cars when the feature is activated.