The driver of the Tesla Model X that crashed on March 23rd did have the autopilot mode engaged. This comes after Uber's deadly crash with a pedestrian, where it has been determined that the self-driving car had not been operating safely. Tesla responded that the driver should have put his hands on the wheel to intervene. Strange curves and barriers can cause problems for the autopilot mode. It's important that any safety driver stay alert when the car is in self-driving mode.