UPDATE: 1 SCE Employee Killed, 3 Injured In Menifee Maintenance Accident

UPDATED AT 7:15 P.M.:  Winchester resident Jose Raul Ros, 38, has been identified by the Riverside County Sheriff-Coroner's Office as the Southern California Edison employee killed in Thursday's accident in Menifee. Click here for the complete report.

UPDATED AT 2:06 P.M.: As investigators continue digging into what caused today's deadly accident in Menifee that killed one Southern California Edison employee and injured three, a spokesman for the utility confirmed the incident took place in a small underground vault as workers conducted maintenance for the utility.

According to SCE local public affairs manager Raymond Hicks, the accident occurred at approximately 7:40 a.m. in an underground vault, no bigger than 14' x 14'. The incident location was Murrieta Road, at Ridgemoor Road, near the nearby Eastern Municipal Water District desalination plant.

Hicks could not confirm the cause of today's accident.

"We are still investigating," he said.

The SCE employees, whose identities have not been released, were doing maintenance work, Hicks confirmed. It's not immediately clear if all four were inside the vault, which Hicks described as a small space with a concrete top and a manhole in the center.

The vault feeds power to the desalination plant, he said. The plant converts salty, nonconsumable groundwater into potable water using a reverse osmosis process

It's unknown if there was smoke, fire or an explosion during the incident, Hicks said.

According to Cal Fire/Riverside County Fire Department spokeswoman Melody Hendrickson, the fatality occurred at the scene, and two of the injuries were caused by smoke inhalation.

Authorities had originally reported one fatality and two injuries in today's incident, but by noon Southern California Edison spokesman David Song issued an updated statement confirming the additional injury.

"Three additional SCE employees were ... injured in the accident and have been transported to area hospitals," Song said.

Hendrickson reported two of the injuries as "minor."

The identity of the employee killed is expected to be released by SCE and the Riverside County Coroner's Office, but not until next of kin has been notified.

"SCE will not release the victim’s name to employees or the public until it has notified the victim's family," Song confirmed.

At press time, Murrieta Road is still closed between Park City Avenue and Ridgemoor Road. 

Hicks said he estimated the road closures to last through at least 3 p.m.

Riverside County Sheriff's Deputy Albert Martinez reported that power lines were down in the area, and Hicks confirmed that at press time the desalination plant is without power.

Martinez said the incident is  but Hicks said he could not confirm that.