WILLARD, Ohio -- Four cars of a 156-car CSX Transportation freight train derailed while the train entered the CSX rail yard here today, snarling rail operations but causing no injuries or public impact.

WILLARD, Ohio -- Four cars of a 156-car CSX Transportation freight train derailed while the train entered the CSX rail yard here today, snarling rail operations but causing no injuries or public impact.

The four cars all contained residual amounts of hazardous materials, but no leak occurred after they derailed but remained upright at about 7:30 a.m., said Carla Groleau, a CSX spokesman.

Railroad operations returned to normal about 4 p.m., Ms. Groleau said.

A Willard police and fire dispatcher said city officials had not been notified about the accident.

Willard, in southern Huron County about 75 miles southeast of Toledo, is the site of a major CSX terminal that sorts railcars traveling through the northwestern part of its 23-state rail network.

The derailment remains under investigation.