The chair of the National Transportation Safety Board urged U.S. lawmakers Wednesday to improve safety measures on freight trains – in light of Norfolk Southern’s train derailment in East Palestine, Ohio, last month.

“The bottom line is there are no accidents,” NTSB Chair Jennifer Homendy said Wednesday. “This derailment, as all accidents we investigate, was 100% preventable.”

At a U.S. Senate Committee on Commerce, Science, and Transportation hearing, Homendy suggested broadening the definition of a high-hazard flammable train, phasing out less protective tank cars, ensuring communities know what’s moving through their towns and requiring railroads to set up crash recording equipment that can capture at least 12 hours of data.

The Feb. 3 derailment, near the rural town of 4,700 people along the Ohio-Pennsylvania border, created plumes of smoke and prompted concerns about air, water and soil quality. Five of the derailed cars contained the highly toxic carcinogen, vinyl chloride, which Norfolk Southern officials released and burned off to prevent an explosion.

Misti Allison, a resident of East Palestine, described the anxiety of not knowing whether she is safe in her own home because of dangerous chemicals released during the controlled burn, which may cause damage that won’t show up for years.

“My 7-year-old has asked me if he is going to die from living in his own home,” Allison said. “What do I tell him?”

She added: “This preventable accident has put a scarlet letter on our town. People don’t want to come here. Businesses are struggling. Our home values are plummeting. Even if we wanted to leave we couldn’t who would buy our homes?”

Headaches, coughing, burning of the skin:Symptoms Ohio residents have experienced after toxic train derailment

Norfolk Southern chief faced bipartisan grilling

Lawmakers on both sides of the aisle took turns grilling Norfolk Southern CEO Alan Shaw and Ian Jefferies, CEO of the Association of American Railroads, an industry group. All agreed that change was necessary, and Shaw apologized repeatedly, though he declined to commit to all changes put forward in a bipartisan bill introduced by Ohio’s Democratic Sen. Sherrod Brown and Republican Sen. J.D. Vance.