Friday night’s cyberattack is “the most significant, successful attack on energy infrastructure” known to have occurred in the U.S., according to Politico.

Colonial Pipeline carries 45% of fuel supplies in the eastern U.S. Some 5,500 miles of the pipeline has been shut down in response to the attack.

While gasoline and diesel prices aren’t expected to be impacted if pipeline operations resume in the next few days, fuel suppliers are becoming “increasingly nervous” about possible shortages, Bloomberg reports.

Colonial said in a statement Sunday while its main fuel lines remained offline, some smaller lines between terminals and delivery points were now operational.

He said “We will bring our full system back online only when we believe it is safe to do so and in full compliance with the approval of all federal regulations”

The US said it’s “working with” fuel pipeline operator Colonial Pipeline to try and restart operations as soon as possible.

The regional emergency declaration by the Department of Transportation’s Federal Motor Carrier Safety Administration is so that fuel supply lines can be kept open.

The emergency declaration covers Alabama, Arkansas, D.C., Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Texas and Virginia.

The DoT agency said in a statement the declaration “addresses the emergency conditions creating a need for immediate transportation of gasoline, diesel, jet fuel, and other refined petroleum products and provides necessary relief.”

The attack is a significant breach of critical infrastructure and comes on the heels of multiple other major cyberattacks on both U.S. companies and the federal government in recent months by foreign actors.

Police had reported the children of 36-year-old Lisa Snyder, Conner and Brinley, had been found hanged with a dog leash in the basement of their Albany Township home on Sept. 23. Snyder had suggested to a 911 dispatcher that Conner was suicidal because of bullying and took Brinley with him because he “didn’t want to go alone.”

Snyder’s arrest was announced Monday by Berks County prosecutors. She was arrested at her home.

“This was a horrific, tragic incident,” District Attorney John Adams told a news conference, Fox 32 reported.

Snyder was also charged with child endangerment and having sex with a dog, the Allentown Morning Call reported.

The paper quoted Adams as telling reporters, “Eight-year-olds, generally, that I am aware of, do not commit suicide so of course, we had questions almost immediately.”

He said that Snyder never returned to the basement where paramedics worked to save her children after she called 911 to report finding Conner and Brinley hanging, the paper reported.

“I would agree that we all may think that a mother of children who are found hanging would make every effort possible to save them,” Adams said. “That was not done in this situation.”

The paper, citing court documents, reported that authorities said the children’s deaths happened a day after Snyder searched “hanging yourself” on Google and visited a website detailing an effective way of hanging a person.

The court papers also quoted authorities as saying that Snyder also conducted searches for “how long to die” from carbon monoxide and for “almost got away with it,” a reference to a true crime television series on the cable channel Investigation Discovery, the paper reported.

The paper also cited an arrest affidavit which stated that in the weeks leading up to the hangings, Snyder sent at least three explicit photos of herself engaged in sexual acts with a black and white dog to an individual who was not named.

According to court records Conner and Brinley were “hanging approximately three feet apart from a single wired cable with a plastic coating,” Fox 32 reported.

Investigators said the dog leash was purchased that morning and was wrapped around the main support beam in the basement and two dining room chairs were knocked over next to the children, according to the station.

The station quoted authorities as saying that a person who lived in Snyder’s house rejected the notion that Conner was suicidal or had been bullied.

Additionally, the station reported that officials said they spoke to numerous school officials, family members and classmates and found no evidence of bullying.