The U.S. Department of Justice has filed a lawsuit against freight train giant Norfolk Southern over its February 3 train derailment in East Palestine, Ohio, seeking to ensure the company pays the full cost of cleanup and any long-term effects, reports The Guardian.

The lawsuit filed in the U.S. district court in Ohio on behalf of the Environmental Protection Agency (EPA) seeks penalties and injunctive relief for the unlawful discharge of pollutants under the Clean Water Act and an order addressing liability for past and future costs.

Meanwhile, it emerged that a team of government officials became sick while investigating the health effects of the toxic train derailment, when they visited the Ohio site earlier this month, the U.S. Centers for Disease Control and Prevention (CDC) told CNN.

Read more: Norfolk Southern Sued by Ohio Over Toxic Train Derailment

The derailment of 38 cars including 11 carrying hazardous materials in the village of East Palestine caused cars carrying toxic vinyl chloride and other hazardous chemicals to spill and catch fire.

The EPA in February issued an order requiring Norfolk Southern to develop plans to address contamination and pay EPA’s response costs.

The EPA administrator, Michael Regan, said the suit will help “ensure Norfolk Southern cleans up the mess they made and pays for the damage they have inflicted as we work to ensure this community can feel safe at home again.”

The railroad did not immediately comment on the lawsuit.

The investigators experienced sore throats, headaches, coughing and nausea, the sort of symptoms that residents in the East Palestine area were experiencing after the derailment and the controlled burn of toxic chemicals from five rail cars that followed, as authorities sought to stave off the risk of the train exploding.