A federal safety alert Thursday warned that crude oil flowing out of new fields in North Dakota may be more flammable than expected, a caution that comes several days after a train carrying about 3.5 million gallons of the same oil crashed in the state and set off a massive explosion.
The accident on the BNSF Railway, the fourth such explosion in North America involving crude oil trains, has fed mounting concerns over public safety as the rail industry sharply increases the use of rail to transport surging crude production in North Dakota, Texas and Colorado.
Following the latest derailment and crash, which forced the evacuation of more than 1,000 residents from the town of Casselton, the National Transportation Safety Board has launched the nation's first broad examination of the safety of moving petroleum by rail.
Trains carrying oil have multiplied across the country as environmental concerns and political maneuvering have delayed approval of a major new pipeline to transport oil to Gulf Coast refineries. The issue may be most crucial for cities in the West, which were often founded and developed by railroads so that main lines go directly through the centers of today's urban areas.
Crude oil shipments by rail have shot up 25-fold in the last several years as producers rush oil from newly developing shale fields to market. California alone has seen a fourfold increase over the last year, with current shipments of about 200,000 barrels a month.
Refinery operators this...