PORTLAND, Ore. (AP) — The Trump administration has angered environmental groups and residents of the Columbia River Gorge by rolling back a 2015 rule on oil train safety.

The Obama administration rule change required trains carrying highly explosive liquids to have electronically controlled pneumatic brakes installed by 2021 — systems intended to help prevent fiery oil train wrecks like the one that happened in the Oregon last year, Oregon Public Broadcasting reported Thursday.

A Union Pacific train derailed in the small Columbia River town of Mosier in June 2016, spilling 42,000 gallons of crude oil and sparking a massive fire that burned for 14 hours.

The U.S. Department of Transportation under President Donald Trump now says, however, that the rule change would cost three times the benefit it would produce and is rolling it back, the station reported. Electronically controlled pneumatic brakes are supposed to be faster than the current industry standard — air-controlled brakes — because the simultaneously signal to the entire train.

Industry officials reacted positively to the news.

Chet Thompson, of the American Fuel & Petrochemical Manufacturers, said in a statement that the rollback a "rational decision."

Conservation groups and lawmakers in the Northwest said the rollback was frustrating, but unsurprising.

"We're definitely frustrated that the Trump administration is weakening standards that are not strong enough to begin with," said Dan Serres, conservation director with Columbia Riverkeeper. "We saw that with the Mosier derailment, potentially if there was a better braking system in place, we wouldn't have seen so many cars come off the tracks."

U.S. Sen. Jeff Merkley, an Oregon Democrat, also slammed the move.

"Oil trains are rolling explosion hazards, and as we've seen all too many times_and all too recently in Mosier_it's not a question of 'if' but 'when' oil train derailments will occur. Degrading oil train safety requirements is a huge step backward and one that puts our land, homes, and lives at risk," he said in a statement.