Pennsylvania and 13 other states, plus the City of Philadelphia, sued the U.S. Environmental Protection Agency on Wednesday over a new rule they say guts "safeguards that prevent or limit harm” from accidents similar to an explosion and fire at a South Philly refinery that released 5,239 pounds of a deadly chemical last year.

The attorneys general say the rule not only violates the Clean Air Act, but also eliminates key safety measures for such explosions, fires, and poisonous gas releases. New Jersey, New York, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Mexico, Oregon, Rhode Island, Vermont, Wisconsin all signed on to the suit filed in U.S. District Court, as did the District of Columbia.

At issue is a 2017 update of the EPA’s Risk Management Program put in place with more stringent regulations on chemical facilities after a fertilizer warehouse exploded in Texas in 2013, killing 15 people. The update was initiated under the Obama administration.

The current Trump EPA, under Administrator Andrew Wheeler, sought to roll back that update.

EPA officials said in their filing announcing the rollback that they had looked at the rule and decided they had “a better approach.” The agency said that the 2017 update imposed additional regulations on "the larger population of facilities that is generally performing well in preventing accidental releases.”

So the agency tossed “amendments to these regulations that we no longer consider reasonable or practicable relating to safer technology and alternatives analyses, third-party audits, incident investigations, information availability, and several other minor regulatory changes.”

The agency said it could achieve the same results, but with lower costs to industry.

An EPA representative said Wednesday that the agency does not comment on pending lawsuits, but pointed to a fact sheet on the rule.

Pennsylvania Attorney General Josh Shapiro said the new rule puts people in harm’s way, and referred to the June 21 fire at Philadelphia Energy Solutions in South Philadelphia.

“Every time we turn around, the Trump administration is working to roll back necessary protections for the people of this country, and this time is no different," Shapiro said in an email. “It is appalling that this is happening after the potentially catastrophic disaster in Philadelphia last year – we should be strengthening regulations, not weakening them.

A coalition of groups has also sued the EPA over the measure.