(NewsNation) — In a Senate hearing on Wednesday, Norfolk Southern’s CEO took responsibility for enhancing safety after the train derailment in East Palestine, Ohio but hedged on support for increased regulation.

CEO Alan Shaw returned to Capitol Hill to face more questioning on the Feb. 3 train derailment in East Palestine that spilled toxic chemicals into the ground, water and air. Lawmakers questioned Shaw on whether the company’s policies led to the derailment while he defended Norfolk Southern’s safety record.

Vermont Sen. Peter Welch pressed Shaw on his company’s role in the accident.

“Let me understand this, you’ve just reluctantly acknowledged that A. It’s preventable, and B., it was your responsibility to prevent it. Am I incorrect?” Welch asked.

“Senator, I’m taking responsibility to enhance safety throughout the entire industry,” Shaw replied.

The committee opened with an overview of bipartisan efforts to prevent another incident from occurring. Ohio Gov. Mike DeWine appeared, making a commitment to the citizens of East Palestine, including announcing that a temporary health clinic set up to treat issues stemming from the accident would become a permanent facility.

Emotional testimony came from an East Palestine resident who talked about the fears families face.

“My seven-year-old has asked me if he is going to die from living in his own home,” Misti Allison told the committee.

Key issues raised included making sure local first responders would be notified if hazardous materials were to be transported through their response area, as well as making sure those responders are equipped with training and equipment to safely respond to such accidents. The length of trains, which can stretch over a mile, was also repeatedly mentioned as a factor in the derailment.

Shaw reiterated Norfolk Southern’s commitment to cleaning up from the derailment, and to making things right with the residents of East Palestine.

Shaw pointed to a preliminary National Transportation Safety Board report that showed the train was operating below speed limits, but admitted more can be done to increase rail safety. Measures he specifically mentioned included phasing out older tank cars for newer, safer models, funding first responder training, and advance warning of hazardous materials transport.

“We support legislative efforts that use science and data to increase the safety of the railroad industry,” Shaw said.

Shaw’s opening statement did not mention a proposed federal regulation that would require a minimum two-person crew for trains. When pressed on the issue, Shaw declined to support regulations for minimum crew staffing, stating only that the company would support data-based regulations.

Sen. Ted Cruz, R-Texas., questioned Shaw on hot box detectors, which are designed to track temperatures of wheel bearings and warn of an impending derailment. The train that derailed passed three detectors, which showed a trend of rising temperatures for the wheel bearing that failed. Cruz asked why the trend of raising temperatures did not trigger an alert and why the company was not able to stop the train before it derailed.

Shaw defended the hot box sensors, saying they worked as designed and there were no defects in the track. He said the company is committed to adding additional hot-box detectors to its network and that the temperatures tracked in the accident did not rise to the threshold needed to trigger a train stop.

Clyde Whitaker, legislative director for the SMART Transportation Division union, told the committee that trending sensor data temperatures is fed to rail company offices and not transmitted directly to train crews in real time, making it more difficult for crews to keep an eye on potential problems.

Whitaker said the technology exists for real-time updates but claimed the rail industry raises and lowers thresholds for stopping trains in order to move more freight. He said the model of precision staffing, used by rail companies, prioritizes profits over safety.

“I believe rail workers should be able to stop any and all work when safety is at risk,” Whitaker said, noting that rail workers fear retaliation if they stop work due to safety concerns.

National Transportation Safety Board Chair Jennifer Homendy testified that the agency made recommendations for safety that included real-time alerts about hazardous materials for first responders in 2013 after another vinyl chloride spill, but those were not implemented by the industry.

Homendy also recommended changes to how trains are classified as highly hazardous; while the train that derailed in Ohio was carrying chemicals like vinyl chloride, which were highly volatile, it did not reach the threshold required to be considered highly hazardous and subject to additional safety regulations.

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