PHILADELPHIA (CBSDFW.COM/AP) – On November 14 of this year – a little more than a month before an Amtrak train derailed near Tacoma, WA killing at least six people – the National Transportation Safety Board concluded that a “lack of a strong safety culture was at the heart” of an Amtrak accident that led to the death of two maintenance workers in Chester, PA last year.

Mike Hoepf, Ph. D. was on the NTSB investigative team that looked into the accident that occurred after an Amtrak train collided with a maintenance backhoe that was working on the tracks. Hoepf said there were many factors that led to the wreck.

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“The investigation uncovered a multitude of safety break-downs due to Amtrak’s weak safety culture,” Hoepf told the board last month. “Managers and organizations with a weak safety culture will fail to proactively address unsafe conditions such as poor training and a lack of equipment. These were precisely the types of unsafe conditions uncovered in this investigation,” he continued.

In his opening statement at the November meeting, NTSB Chairman Robert Sumwalt said, “Despite the emphasis on rules compliance, investigators did not find a culture of compliance at all.” Sumwalt continued, “Rather, they found a culture of fear on one hand, and a normalization of ‘deviance from rules’ on the other hand.” Sumwalt said that strong safety culture and a culture of fear cannot coexist.

Workers told investigators that they felt Amtrak had been emphasizing on-time performance over safety, belying the big, red “think safety” signs it posted in employee lounges and its threats to fire workers who broke certain rules.

NTSB chairman Robert Sumwalt said Amtrak’s grab bag of priorities created a culture of fear and non-compliance that encouraged workarounds to “get the job done.” Amtrak’s unions, wary of its approach, refused to participate in two of the railroad’s safety programs, Sumwalt said.

Lapses in communication and a lack of required equipment left the Chester workers with no protection and little warning as the Savannah, Georgia-bound Palmetto train streaked toward their backhoe at more than 100 mph.

A foreman who had just taken charge of the maintenance crew did not ask a dispatcher to keep routing trains away from the workers, investigators said, nor did he have a device meant to prevent trains from running on the same tracks as workers, even though Amtrak rules require its use.

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In all, investigators flagged more than two dozen safety issues in the crash, far more than in most crash investigations, according to NTSB board member Earl Weener. Backhoe operator Joseph Carter Jr., 61, and supervisor Peter Adamovich, 59, were killed and about 40 passengers were injured.

“Had any of these issues been addressed, the accident may have been prevented,” NTSB investigator Joe Gordon said at a public meeting on the crash at the agency’s Washington headquarters.

According to the Associated Press, Amtrak’s co-chief executive officers, Richard Anderson and Charles “Wick” Moorman sent a letter to employees last month updating them on steps the railroad has taken to transform its safety culture since the crash.

They include hiring a new head of safety, compliance and training, issuing alerts and advisories to remind workers of rules and an improved worker-protection training program.

“Our customers expect us to operate safely and our jobs and lives depend on it,” the co-CEOs wrote. “We can and will do better. Our pledge to you is that we will do everything possible to help move us forward.”

There is still no word yet on the cause of this latest train crash near Tacoma, WA Monday.

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)