US investigators said on Tuesday (Jan 28) that the helicopter carrying Kobe Bryant was involved in a "high energy impact crash" when it slammed into a hillside in foggy weather on Sunday, killing the basketball star and eight others, including his 13-year-old daughter.br br The National Transportation Safety Board (NTSB) br estimated the twin-engine Sikorsky S-76B hit the ground at a speed of more than 610 metres (2,000 feet) per minute.