Shanda Long was driving home from dinner Tuesday night when she stumbled upon the scene of what Las Vegas police said may have been a suicide attempt at an NV Energy substation in the southeast valley.

An accident near a substation at 5640 Stephanie St. in Henderson triggered a temporary blackout Tuesday. The substation is located at the Clark Generating Station. (Rachel Crosby/Las Vegas Review-Journal)

Shanda Long was driving home from dinner Tuesday night when she stumbled upon the scene of what Las Vegas police said may have been a suicide attempt at an NV Energy substation in the southeast valley.

The incident triggered a power outage that left more than 13,000 southeast valley customers in the dark that evening.

Long first noticed the flashing lights of several first responders at the 5640 Stephanie St. site, near Russell Road and U.S. Highway 95. She saw three fire trucks, two ambulances and a handful of NV Energy trucks stopped as she pulled past.

But with a closer look, she saw what they were responding to: a man — seemingly lifeless — burned so bad his body and clothes looked charred.

“The guy was laying on top of a transformer between four big power lines,” Long, 30, said. “They had like six to eight EMTs holding a ladder trying to get him down.”

The outage happened about 8 p.m., and NV Energy initially attributed the cause to an “accident.” Company spokeswoman Jennifer Schuricht later said a man was trespassing on substation property, which is fenced in, topped with barbed wire and has a single, secured entry point. She added that the man was not an employee.

“It is not common for us to see trespassers,” Schuricht said.

Clark County Fire Department crews were called to the scene at 8:54 p.m., about an hour after the power first went out, per dispatch records. Deputy Chief Jeff Buchanan was not able to explain the gap in time between the beginning of the outage and the time crews were called, but said responders were told someone at the substation was in “cardiac respiratory arrest.”

Long was near the substation at about 9:10 p.m., and she watched as crews loaded the man into an ambulance. He was soon transferred to a helicopter that airlifted him to University Medical Center, where he was treated for burns that covered more than 70 percent of his body, Buchanan said.

On Wednesday, the man was still in “extremely critical condition” and remained in the hospital’s burn unit, Metropolitan Police Department spokesman Larry Hadfield said. It was hospital officials who determined the man may have been trying to kill himself at the substation, citing signs of self-mutilation on the man besides the burns, Hadfield said.

Should he recover, and should NV Energy decide against pressing charges, the man will be submitted for mental-health evaluations through a “Legal 2000,” which allows authorities to hold individuals for up to 72 hours who may be a danger to themselves or others, Hadfield said.

“We have not determined if we will press charges,” Schuricht said of NV Energy.

It was still unclear Wednesday night how the man was able to enter the facility or who initially called police to report a medical emergency at the site. Power was restored to the southeast valley Tuesday about 9:45 p.m.

But at least two hours after the lights came back on, NV Energy crews were still at the far southeast end of the site, working on the fried equipment.

“My husband thought maybe he was trying to steal the copper wire,” Long said of the man. “On the ground, underneath where the man was stuck, was a big pair of red-handled cutters. But of course nobody really knows.”

Las Vegas Review-Journal writer Christian Bertolaccini contributed to this report. Contact Rachel Crosby at rcrosby@reviewjournal.com or 702-387-5290. Find her on Twitter: @rachelacrosby Contact Christian Bertolaccini at cbertolaccini@reviewjournal.com and 702-383-0381. Find him on Twitter: @bertolaccinic