Questions mount about the safety of shipping North Dakota crude oil

Hundreds of rail cars filled with North Dakota crude oil pass through Minnesota each day. That reality has state and federal leaders worried about safety.

Some — including Gov. Mark Dayton — argue oil companies should take steps to reduce the oil's volatility before loading it onto train cars. Proponents say that would minimize the chance for explosions if a train were to derail or crash. Dayton sent a letter to North Dakota's governor this week calling for stricter standards on the quality of oil shipped by rail.

But industry reps say that simply isn't necessary — that their oil is safe to ship.

MPR's Cathy Wurzer spoke with Chester Dawson, a senior correspondent at the Wall Street Journal, who has been covering this issue from North Dakota.