For the Record' update: Could China take out the U.S. power grid?

The United States power grid and other utility systems are vulnerable to threats from China and "probably one or two other" nations that could take them offline, according to testimony during a House Intelligence Committee hearing on cybersecurity threats Thursday.

Adm. Michael Rogers, director of the National Security Agency and head of U.S. Cyber Command, told the committee there are nation-states and groups that have the ability to “enter our systems, to enter our industrial control systems and to shut down [and] forestall our ability to operate, our basic infrastructure."

"That has the potential to lead to some truly significant, almost catastrophic failures if we don't take action," he said.

The threats to the U.S. power grid were the subject of For the Record's episode "Unguarded" in April.

In his testimony, Rogers pointed to cases where foreign nations and other groups have successfully hacked into the control systems for critical infrastructure like the electrical grid, water and fuel pipelines.

"What we think we're seeing is reconnaissance by many of those actors in an attempt to make sure they understand our systems so that they can then, if they choose to, exploit the vulnerabilities within those control systems," Rogers said.

Many complex networks such as utilities require Supervisory Control And Data Acquisition — or SCADA — systems to run, but those systems are vulnerable to hacking. Rogers said they are one of his biggest concerns.

"People will often ask me, 'What are the coming trends that you see?' I think the industrial control system and the SCADA piece are big growth areas of vulnerability and action that we're going to see in the coming 12 months," Rogers said.

He testified that the impact of a successful cyberattack on utilities could be devastating.

"Once you're into the system and you're able to do that, it enables you to do things like if I want to tell power turbines to go offline and stop generating power, you can do that," he said. "If I wanted to segment the transmission system so that you couldn't distribute the power that was coming out of the power stations, this would enable you to do that."

Rogers added, "This will be truly destructive if someone decides that's what they want to do."

Learn more about the threats to the electrical grid and other utilities by watching "Unguarded" on demand. Here's a clip: