ST. STEPHEN — Officials were optimistic that a road blocked by a coal train derailment early Tuesday would be open for traffic this morning, while the investigation continues into what caused a section of fully loaded cars to tip over.

No one was reported injured in the crash that took down pine trees, chewed up soil and twisted rail lines into bent spaghetti.

The accident occurred shortly after 6 a.m. near mostly rural S.C. Highway 45, roughly 100 yards from St. Stephen Middle School.

Crews were assessing the number of cars that were damaged and the severity of the damage. Early estimates said at least five cars, out of a train of about 90, were tossed around. All were loaded with coal destined for the nearby Santee Cooper power plant.

One woman said her household heard the boom of the crash but didn't immediately register what happened.

"We were so used to the train going by, we're used to the noise," said Barbara Bobbitt, who lives about 70 yards from the wreck site.

St. Stephen Police Chief John Waters said the road closure probably affected hundreds of drivers. The road, locally identified as Ravenell Drive, was cut off.

Area traffic was routed around the accident scene throughout the day. Early on, officials confirmed that the wreck did not pose a serious environmental hazard, Waters said.

Within six hours of the accident, a caravan of hired heavy equipment was on the scene, including bulldozers to begin the weighty task of clearing the wreckage, though much of the damage was surrounded in thick pine forest growth and not easily accessible.

Bob Sullivan, CSX rail media relations director, said the cause continues to be under investigation and there is no preliminary theory to announce.

John Hawkins, another CSX communications official, said the train, with two locomotives, had originated in Russell, Ky., and was loaded with coal in Cayce. The line serves Georgia Pacific and Santee Cooper.

The train derailed after pulling onto a straight section of track that heads toward the Santee Cooper power plant in Cross. The derailment is not expected to have an immediate impact on Santee Cooper's on-site coal supply, which by one estimate was at least two months.

The Highway Patrol would determine when the road is safe to open for traffic, a spokesman said.

Reach Schuyler Kropf at 937-5551 or skropf@postandcourier.com.