July 26 (Reuters) - U.S. railroad Union Pacific ( UNP )

interfered in a federal safety audit after employees were

coached how to respond, prompting the federal rail agency to end

the review, the chair of the Senate Commerce Committee said on

Friday.

Senator Maria Cantwell said she was opening a probe into

Union Pacific's ( UNP ) actions after the Federal Railroad

Administration told the committee this month it was forced to

discontinue its assessment "due to Union Pacific's ( UNP ) actions to

undermine the integrity of the assessment process."

She asked the company to provide all documentation regarding

the safety culture audit, along with policies and plans to

improve its safety culture.

Union Pacific ( UNP ) said safety is its "key foundational pillar"

and would respond to Cantwell's letter.

The FRA did not immediately comment.

Cantwell said the FRA found that employees companywide had

been coached to provide specific responses to safety inspector

surveys and report the interactions they had with inspectors to

supervisors.

Cantwell said she was "deeply concerned about these FRA

findings and the chilling effect the Union Pacific ( UNP ) actions have

on employee reporting of safety issues." She added she is

concerned this indicates a weak safety culture and cited Union

Pacific's ( UNP ) derailment rate that is 30% higher than the

next-highest major railroad.

In June 2023, the FRA said it would conduct safety

assessments of all major U.S. railroads following the February

2023 derailment of a Norfolk Southern ( NSC )-operated train in

Ohio.

Last month, the chair of the National Transportation Safety

Board said Norfolk Southern ( NSC ) threatened the board, sought to

manufacture evidence and failed to provide documents during its

investigation of the Ohio derailment.

Cantwell's committee in May 2023 approved sweeping rail

safety legislation to mandate the use of technology that can

identify equipment failures and boost fines for safety

violations, but that bill has stalled in Congress.