The FBI captured two people, one of them a nationally known neo-Nazi leader, before they could launch an attack on Baltimore’s power grid that could «utterly destroy this entire city,» authorities said Monday.

The suspects, Brandon Russell and Sarah Clendaniel, were arrested last week in Florida and Maryland, respectively, authorities said.

Federal authorities described the alleged plot as «racially or ethnically motivated.» Over 61% of Baltimore residents are black.

Russell is one of the founders of the Atomwaffen Division, a neo-Nazi group bent on «heralding the collapse of civilization,» according to the Southern Poverty Law Center. The group admires Charles Manson and supports «the idea of ​​lone wolf violence,» according to the Anti-Defamation League.

Sarah Clendaniel is suspected of an alleged plot to attack Baltimore’s power grid.nbc news

The alleged plot was first flagged in June of last year after an FBI informant claimed to have been contacted by Russell, who wanted to «attack electrical substations and provided guidance on how to do maximum damage,» according to the criminal complaint filed against the pair.

Russell then connected the informant with Clendaniel, a Maryland resident, to discuss plans for an attack on stations in and around Baltimore, federal authorities said.

The couple and the informant worked urgently, as Clendaniel said he was terminally ill with kidney ailment «and was unlikely to live more than a few months,» according to the criminal complaint.

Clendaniel had five stations in the crosshairs, authorities said, in Norrisville, Reisterstown and Perry Hall, Maryland, and two more «in nearby Baltimore,» according to the complaint.

The attacks on the five would «‘ring’ around Baltimore and if they attack multiple of them in the same day, they ‘would completely destroy this entire city,'» Clendaniel allegedly said in a recorded conversation, the complaint revealed.

Thomas J. Sobocinski, special agent in charge of the FBI’s Baltimore office, said the suspects were serious about their efforts to shut down the city ​​of 580,000.

“The defendants were not just talking, they were taking action to carry out their threats and further their extremist goals. Russell provided directions and location information. He described attacking power transformers as the best thing anyone could do,” Sobocinski said.

«Their actions threatened the electricity and heat of our homes, hospitals and businesses.»

Attacks on the nation’s power grid became apparent in December, following two high-profile incidents.

There were shootings in two electrical substations in central North Carolina in early December, authorities said. At the peak of Duke Energy’s blackouts, more than 45,000 homes and businesses were left in the dark.

That incident was followed by attacks on four power substations over Christmas weekend near Tacoma, Washington, when about 14,000 homes and businesses were forced to live without power, authorities said.

This is a developing story. Please check for updates.