An electric Tesla Semi truck crashed over the weekend in Dayton, Nevada, killing two people. It was the first known crash of a Tesla Semi, and it raises questions about its safety features, according to the Los Angeles Times. 

The collision occurred at around 7 a.m. on Sunday in Lyon County, about 40 miles east of Reno. Tesla is building the electric Class 8 truck and has plans to ramp up production. 

While the trucks lack the Full Self-Driving mode available in Tesla cars, Tesla’s website says they come standard “with active safety features that pair with advanced motor and brake controls to deliver traction and stability in all conditions.”