The unattended Montreal, Maine & Atlantic Railway train was parked overnight on a rail line before it came loose, hurtling down a seven-mile incline and slamming into the center of Lac-Megantic. Donald Ross, chief investigator for the Transportation Safety Board of Canada, said Friday it remained unclear whether mechanical problems or human error were to blame.
In the first half of this year, U.S. railroads moved 178,000 carloads of crude oil. That's double the number of the same period last year and 33 times more than the same period of 2009. The Railway Association of Canada estimates that as many as 140,000 carloads of crude oil will be shipped on Canada's tracks this year, up from 500 carloads in 2009.
Last year, 663 rail cars carrying hazardous materials derailed or were damaged in the U.S., a decline of 38 percent from 1,072 incidents in 2003, according to the Federal Railroad Administration. That's comparable to the total number of train accidents per million miles traveled, which fell 43 percent over the same period, and the number of derailments, which fell 40 percent.
While crude transport by rail has grown quickly, it is still a relatively small part of train traffic and the crude trade.
Just 1.4 percent of U.S. rail traffic in the first half of this year was crude oil, according to the Association of American Railroads. Pipelines and tankers remain the most important way to move crude. Railroads and trucks together supplied just 3 percent of the crude that arrived at refineries last year, according to the Energy Department.