According to Koenigsegg, the crash happened during Industry Pool track testing. The company was working on vehicle development and preparing for a possible record run at the famous track. Fortunately, it seems the driver was all right. Koenigsegg said he was taken to the hospital and released the same afternoon.
Koenigsegg didn't give a specific reason for the crash. The company only said that it tries to be as safe as possible, but track-testing high-performance cars is always risky. A photographer for MotorAuthority said the One:1 came too fast into the corner and couldn't slow down enough to avoid crashing into the barrier. In the video above, you can see the telltale tire tracks leading up to the crash site.
MotorAuthority also reports that Koenigsegg plans to rebuild the wrecked One:1. We would certainly be happy to see it resurrected since there were only seven total (six production and one prototype) built, and it would be a shame to lose any of them forever.