Source : New York ( CNN ) -- NTSB investigators looking for video of bus driver 's casino activities before the accident . Witnesses say police vehicle rolled over rumble barrier . Driver of tractor - trailer tells bus driver account of crash involvement , police source says . Witness say bus was traveling very fast before accident that killed driver .
Source : NTSB investigators looking for video of bus driver 's casino activities before the accident . Witnesses say police vehicle rolled over rumble barrier . Driver of tractor - trailer tells bus driver account of crash involvement , police source says . Witness say bus was traveling very fast before accident that killed driver .