The rocket was undergoing a static fire test of the stage, in which a vehicle is clamped to a test stand while its engines are ignited, when the booster broke free. According to a statement from the company, the rocket was not sufficiently clamped down and blasted off from the test stand “due to a structural failure.”
Video of the accidental ascent showed the rocket rising several hundred meters into the sky before it crashed explosively into a mountain 1.5 km away from the test site.
I feel better knowing that Chinese military partners get to feel the joy as well. (Curbs can be a bitch sometimes…)