What happened
During the initial phase of the landing rollout, the pilot experienced a bounce upon first contact with the runway surface. In an effort to regain control and arrest the descent, the pilot applied additional power to lift the aircraft momentarily before quickly reducing throttle settings.
This sequence of power adjustments caused the aircraft to adopt a nose-high pitch attitude. The aerodynamic configuration at this moment resulted in an aerodynamic stall. Following the stall, the aircraft descended rapidly and impacted the runway surface with significant vertical force for a second time.
Upon this hard touchdown, the aircraft began to porpoise, oscillating vertically along the runway centerline. The structural integrity of the landing gear was compromised during this violent motion, leading to the collapse of the nose landing gear assembly. With the nose gear no longer supporting the front of the aircraft, it skidded off the paved surface.