Federal investigators say it’s “unacceptable” that railroad regulators haven’t enacted rules intended to prevent accidents like the fatal Amtrak crash outside Columbia earlier this year.

The National Transportation Safety Board suggested new safety measures just days after a passenger train slammed into parked freight cars in February, a crash that killed two crew members and injured scores of people.

The NTSB’s proposal was to have trains slow down when traffic signals aren’t working so they can make sure rail switches are set correctly. The Amtrak train hit a switch set the wrong way before it crashed, but its crew only realized the problem seconds before impact.

The Federal Railroad Administration, which oversees the nation’s rail carriers, has not implemented such a rule. Instead, it put out an advisory, which the NTSB said wasn’t enough during a hearing Tuesday in Washington.

The railroad agency wasn’t immediately available for comment Tuesday.

Amtrak says it has self-imposed a similar rule. Its trains now move more slowly when they come up to a switch without a working signal, and it now reviews every section of track with signal outages before sending trains through it. Freight railroads don’t appear to have undertaken similar measures.

It’s not a common problem, but it’s not a rarity either: Amtrak has studied more than three dozen outages since March, according to Justin Meko, Amtrak’s vice president for compliance and safety.

In some cases, it has cancelled service because of outages, Meko said at the NTSB hearing. In others, it has put passengers on buses to shuttle them around problem areas.

The February crash happened in the middle of a February night in Cayce, a Columbia suburb. Signals weren’t working because CSX Corp. was installing a new safety system on its tracks and crews didn’t finish their work during the day.

CSX dominated much of Tuesday’s hearing, which was intended to sort through how safety checks and regulations failed in Cayce. Investigators took aim at how a management shakeup at CSX might have affected the railroad’s safety culture.

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NTSB chair Robert Sumwalt, a Columbia resident, pointed to the messages CSX sent its investors in the months before the crash. In one presentation, the company touted the targets it met in 2017,  such as earnings growth and shareholder payouts.

Sumwalt asked why safety wasn’t one of them. Was it not a goal, he asked, or were the company’s safety goals not met? CSX officials responded that it had been concerned with safety, even if it wasn’t on the investor presentation. The company didn't respond to a request for comment.

CSX officials acknowledged that their organization had been upended in 2017 under late CEO Hunter Harrison, who pushed to make the railroad run more efficiently with fewer workers before falling ill and dying in December. Matt Meadows, an executive overseeing the railroad’s rules, said he saw “a vast amount of change happening in a short amount of time.”

But Meadows said the company was taking steps to shore up its safety measures. It hired an outside consultant to study its culture, for instance, and it created a tip line for employees to report safety problems two months ago. He said he’d noticed a “huge adjustment” in the last six months, and that the company had taken steps to “refocus” on safety.

Deep into hours of questioning, Sumwalt pulled out his iPhone and read aloud the definition of “refocus.” He asked if the company wasn’t focused on safety risks to begin with.

Meadows declined to answer.

Reach Thad Moore at 843-937-5703. Follow him on Twitter @thadmoore.