(NewsNation) — A former FBI agent is calling for more security at electric substations following an attack on one in North Carolina that left tens of thousands of people without power.

The FBI is now seeking search warrants in its investigation into that attack that occurred Saturday in Moore County, North Carolina. Federal investigators want phone records that could indicate who was near the substations at the time they were shot up.

Stuart Kaplan, a former FBI special agent, said the attack should be a catalyst for utility agencies to get serious about stepping up security at infrastructure sites.

Watch his interview on “Rush Hour” above.