Police say Amber Leigh Mills and Brian Griffin Rey climbed a fence that was clearly marked with warning signs just before midnight Sunday. Once inside the substation, one of them touched a piece of equipment.
The two were taken to the Jaycee Burn Center in Chapel Hill. Authorities say Rey suffered the worse injuries. He is hospitalized in critical condition and Mills is in serious condition.
Authorities say the substation's 23,000 volts could have killed the couple.
After the violent shock, one neighbor saw Mills running to her apartment before an ambulance rushed her away.
"She was kind of hysterical," NC State student Aaron Billups said. "She said the power station blew up and she needed to go inside. She was in shock at that point."
Progress Energy says trespassers climb into one or two substations a year, usually to attempt a copper theft. The results are often violent.
"You don't actually have to touch something inside a substation for there to be a hazard," said Mike Hughes, Progress Energy.
The outage left 12,000 customers, including nearby Centennial Ridge Apartments without power.
One Centennial Ridge resident learned about the outage via text message.
"We got a text saying the power was out, then we saw the ambulances coming and we were sort of scared," Jessi Smith said.
Investigators say they will question the pair, but are allowing them time to recover. Right now, authorities do not know why the two jumped the fence.
Police say Mills and Rey may face misdemeanor trespassing charges.