NTSB interviews engineer, conductor of train with ethanol that derailed in South Dakota

Federal investigators looking into a weekend train derailment in rural South Dakota on Monday began to interview the engineer and conductor of the train, seven of whose ethanol tanker cars left the tracks, causing at least one to catch on fire.

National Transportation Safety Board spokesman Terry Williams said the seven investigators who were deployed to the derailment site are inspecting the train's cars and gathering information from the crew, as well as myriad documents, including track and train inspections. The 98-car train derailed in a rural part of Bon Homme County awash in corn fields between the towns of Scotland and Lesterville.

"They are doing a thorough examination of those cars," Williams told The Associated Press Monday. Investigators arrived at the site Saturday night and began examining the tanker cars Sunday.

No one was hurt when the train, operated by Burlington Northern Santa Fe, derailed about 6:15 a.m. Saturday. The train was heading from Mina to Deer Park, Texas, and was traveling 10 mph, which was the allowed speed, Williams said.

The railway has indicated the train derailed over a small bridge that spans a dry creek. Three tankers were compromised and lost their contents.

A detailed investigation will take investigators at least a year to complete. The NTSB will have access to the tankers throughout the probe.

"We look for the cause of the accident, but also any contributing factors," Williams said. "We like to say that we look at the man, the machine and the environment."

A spokeswoman for BNSF didn't immediately respond to a request for comment Monday. The railway has previously said it expects to reopen the tracks at 10 p.m. Tuesday.