Crude oil shipments by rail have increased by over 400 percent since 2005, according to the Association of American Railroads' Annual Report of Hazardous Materials. The NTSB said it’s concerned that major loss of life, property damage and environmental consequences can occur when large volumes of crude oil or other flammable liquids are transported on a single train involved in an accident, as seen in the Lac Megantic, Quebec, accident, as well as several accidents the NTSB has investigated in the U.S.