Racing in any form has tremendous amount of risk. The scariest one of all comes in the form of mechanical failure, especially brakes. According to the description of the video seen below, the colliding car (which look like a BMW 3 series) experienced brake failure upon entering the esses of this road coarse. The turn is located after a very long straightaway, which meant the impact speed may be significant, as seen in the clip.
Also according to the video both drivers are apparently ok from this crash. That’s quite the miracle as the black BMW received a tremendous jolt, spinning them off the track, resembling something that would be a lot more fatal.