Witness : `` I could n't see ( the explosion ) directly , but it was deafening , '' he said . The cause of the accident is not clear ; authorities will investigate . Officials believe no toxic substances were aboard . Driver of train is only person injured . Witness : ' Deafening ' explosion followed collision .
Witness : The cause of the accident is not clear ; authorities will investigate . Officials believe no toxic substances were aboard . Driver of train is only person injured . Witness : ' Deafening ' explosion followed collision .