PORTLAND, Ore. — Federal investigators Thursday blamed the Union Pacific Railroad for a fiery oil train derailment along the Oregon-Washington border, saying the company failed to properly maintain its track.

Preliminary findings on the June 3 derailment in the Columbia River Gorge raise questions about why the company didn’t find the broken bolts that triggered the wreck when it inspected the tracks before the derailment, which released 42,000 gallons of crude oil and sparked a massive fire that burned for 14 hours. Union Pacific faces potential penalties for safety violations, officials said.

Advanced electronic brakes proposed by regulators could have made the derailment less severe, Federal Railroad Administrator Sarah Feinberg said. The brakes could have reduced the number of cars that went off the tracks and prevented the one that first burst into flames from being punctured, she said.

“We’re talking about upgrading a brake system that is from the Civil War era,” Feinberg said. “It’s not too much to ask these companies to improve their braking systems in the event of an accident so fewer cars are derailing.”

The railroad industry, through the Association of American Railroads, has lobbied against new braking requirements, saying they would provide “minimal safety benefits” at a cost of $3 billion.