TACOMA, Wash. (AP) — Two men have pleaded guilty to vandalizing power substations in Washington state in attacks that left thousands without power on Christmas Day.

Jeremy Crahan, of Puyallup, admitted Wednesday in U.S. District Court in Tacoma that he and Matthew Greenwood conspired to cut electrical power in order to break into ATM machines and businesses and steal money, Acting U.S. Attorney Tessa M. Gorman said in a news release.

According to the plea agreement, Crahan, 40, and Greenwood, 32, damaged four power substations on Dec. 25, 2022. The substations targeted were the Graham and Elk Plain substations operated by Tacoma Power and the Kapowsin and Hemlock substations operated by Puget Sound Energy.

In all four cases, the men forced their way into fenced areas surrounding the substations and damaged equipment to cause a power outage.

Crahan admitted that he helped plan the scheme and primarily served as a lookout that day.

Afterward, the men plotted additional ways to cause power outages by felling trees in order to cut power and burglarize businesses and steal from ATMs, Gorman said. Law enforcement arrested both men in late December before they tried that plan, according to the news release.

Greenwood, also of Puyallup, pleaded guilty in April to conspiracy to destroy energy facilities. After his arrest, Greenwood went to a substance abuse treatment program.

Both face up to 20 years in prison.

Officials have warned that the U.S. power grid needs better security to prevent domestic terrorism and after a large outage in North Carolina last year took days to repair.