The helicopter that crashed into a foggy mountain near Calabasas, Calif., on Sunday, killing the N.B.A. legend Kobe Bryant and eight other people, fell quickly in what an investigator said was a “high-energy impact crash.” Jennifer Homendy, one of five board members of the National Transportation Safety Board, said on Tuesday afternoon that investigators had recovered an iPad and a cellphone from the wreckage, which was strewn across more than 500 feet on the side of a rugged hill.