Train cars and road vehicles sit below a railroad bridge Dec. 19, 2017, after an Amtrak train crash a day earlier in DuPont, Wash. (Elaine Thompson/AP)

An Amtrak train derailed in Washington state in December 2017 because the lack of an automatic braking system allowed the engineer to enter a 30-mile per hour curve too fast due to his inadequate training on the route and the equipment, the National Transportation Safety Board concluded Tuesday.

The crash, which killed three passengers and injured 65 others, came on the maiden trip on a new route, and the NTSB said that the engineer appeared confused and missed two signs warning of the upcoming curve. He also was unfamiliar with a warning signal that activated, alerting him that he was going too fast as he approached the curve, investigators said.

The board said a contributing factor to the severity of the crash was the Federal Railroad Administration’s decision to approve the use of rail cars that did not meet U.S. safety standards. The Talgo series six-rail-car set “poses unnecessary risk to railroad passenger safety when involved in a derailment or collision,” the panel said.

The board also said seat belts should be used aboard trains and that frontward and inward-facing recorders should be used in all train operations.

Despite the engineer’s confusion, NTSB Chairman Robert Sumwalt said the “engineer was set up to fail,” noting that investigators “identified failures up and down the line.”

In addition to the FRA, the report cited missteps by the Central Puget Sound Regional Transit Authority, the Washington State Department of Transportation and Amtrak.

The panel noted repeatedly that the crash could have been avoided if the automatic braking system known as Positive Train Control had been installed. Commonly called PTC, the system would kick in if an engineer were going too fast.

The hearing pointed out that while Amtrak operated the train, it was running on tracks owned by the transit authority.

“Ideally, Sound Transit could have waited until PTC was completely installed and operational before allowing passenger service” on the new route, said Ryan Frigo, an NTSB investigator.

In addition to the deaths and injuries, the 7:30 a.m. crash on Dec. 18, 2017 near DuPont, caused more than $40 million in damage to the train and the vehicles on the highway below it.

Board member Jennifer Homendy asked Mike Hiller, who studies crashworthiness for the NTSB, whether PTC would have prevented the wreck.

“Yes,” Hiller said.

“This would have absolutely prevented this accident,” Homendy said.

The NTSB has recommended PTC for decades, saying that in the past 50 years the agency has investigated 150 rail accidents that the automatic braking system could have prevented, killing 303 people and causing 6,800 injuries.

But Congress — faced with railroad lobbyists who said the cost would be exorbitant — was slow to act on the NTSB recommendation. It took one of the worst train wrecks in modern history to spur the lawmakers into action: the 2008 head-on collision between a Metrolink commuter train and a Union Pacific freight train in a Los Angeles neighborhood that killed 25 people and injured 102.

Afterward, Congress mandated that PTC be installed on 58,000 of the nation’s 134,000 miles of railroad track, including those most heavily used by passenger rail lines.

The railroad industry said installing computers in locomotives, putting transponders in towers along the rail bed to communicate with those computers and training workers to use them would cost billions. In 2015, they prevailed on lawmakers to extend the PTC deadline by three years, to the final day of 2018.

Congress also agreed that for railroads that made “substantial progress” toward meeting that deadline, the envelope would expand for another two years until the end of 2020.

Racing into the curve at more than twice the posted speed limit, the train in the DuPont crash spun from the tracks in a jumble of cars and locomotives, some staying upright while others toppled onto their sides and one turned over completely.

Three passengers were ejected from the train and killed, and 57 more aboard the train were injured. The curve grew sharpest as it neared an overpass to busy Interstate 5, south of Tacoma, Wash. The train tumbled down onto the lanes of that highway, with the overturned rail car wedged under the bridge that would have carried a train — had it gone more slowly — over the highway. The 200-ton locomotive and 65-ton passenger cars came raining down on either side of the bridge, with one train car balanced precipitously against another that had fallen below it.

Eight people driving on the interstate were injured when they crashed into train cars.

Though Amtrak’s Cascade line dated to at least 1927, previously it had taken a route that skirted the Puget Sound from Tacoma to a point south of DuPont. There had been several test runs on the new track, and the engineer, who was seriously injured, told the NTSB just afterward that he would not have made the trip if he had “any reservations about his readiness to operate the train.”

The DuPont wreck came less than three years after a similar Amtrak derailment in Philadelphia, where an engineer entered a curve at twice the posted speed limit, a crash that killed eight and injured 159 people.

In the Philadelphia wreck, the NTSB concluded the engineer became distracted by rock-throwing aimed at a nearby train and lost “situational awareness.” The board also cited the lack of PTC, which would have automatically slowed the train as it entered the curve, as one of the causes.