(NewsNation) — A series of vandalism reports throughout the country — including a pair of outages in North Carolina that left thousands without power for days — points to vulnerabilities in securing some of the nation’s power grids.

Following an incident last week that caused widespread power outages in North Carolina, Nexstar’s WNCN visited two substations and found they were secured by only a chain-link fence and a lock. There were no visible security cameras or guards.

Law enforcement has recently been called to investigate suspected acts of intentional vandalism in areas including Florida and Washington state.

A substation in the Portland, Oregon, area was damaged late last month. The person or people responsible had broken through a security fence and damaged equipment in the substation yard, said Doug Johnson, a spokesman for the Bonneville Power Administration.

“You always know there’s a threat out there,” Johnson said. “We’re always looking for ways to further harden the system against sabotage. But for now, we are in compliance with the rules as they exist today.”

Other power companies and industry representatives told NewsNation they’re following industry standards and federal guidelines.

But new efforts to target power grids could be emerging. An August memo by federal law enforcement detailed the time a suspected white supremacist entered an online chat and shared a file that contained substation locations in the U.S., Canada and Mexico.

The database uses public information from the Department of Homeland Security and shows the exact coordinates of what’s believed to be every substation in the U.S. — including some of those recently struck in North Carolina, Florida and Oregon.

KRON On is streaming news live now

Duke Energy, the company impacted in North Carolina, previously issued the following statement:

We can’t comment on any ongoing legal proceedings or investigations. However, given the nature and scale of our operations, we – alongside federal, state and local law enforcement and security officials and industry partners – are continuously assessing and evolving our measures to protect our critical infrastructure.  That partnership includes helping bring anyone, who damages our system, to justice. 

Duke Energy

The North Carolina power outage remains under investigation.