May 17 (UPI) -- Federal investigators say Tesla's autopilot system has been connected to another death, from a Model 3 crash in Florida this spring.
While the National Transportation Safety Board's preliminary report Thursday didn't assign blame, it's heightened concerns about Tesla's autonomous driving system.
The accident happened in March in South Florida when the vehicle crashed into a semi going 68 mph on a road with a speed limit of 55 mph, the report said. The 50-year-old driver of the Tesla died when the car's roof was sheared off.
The report said the Model 3's autopilot system had been engaged for about 10 seconds at the time of the crash and the driver didn't have his hands on the wheel for several seconds. A video from the vehicle didn't show the driver take any evasive maneuvers.
Tesla said the driver "immediately removed his hands from the wheel" after engaging the autopilot, and said the autonomous system wasn't used at any other time.
The death is the third involving a Tesla autonomous vehicle in three years.
Apple engineer Walter Huang died in a crash last year in Northern California that involved a Tesla Model X SUV with the autopilot system engaged. Relatives are now suing Tesla for his death. Another driver in Florida was killed in a 2016 crash.
Tesla had touted its autopilot system in a first-quarter report, saying that it was involved in one accident for every 2.87 million miles driven when the system was engaged.
"Either Autopilot can't see the broad side of an 18-wheeler, or it can't react safely to it," he said. "This system can't dependably navigate common road situations on its own and fails to keep the driver engaged exactly when needed most."