IRWINDALE, Calif. >> A man who shot four people, killing two, at a utility office east of Los Angeles before turning the gun on himself was a 48-year-old company employee from Southern California, authorities said Saturday.

Investigators identified the shooter as Andre Turner of Norco in Riverside County and ruled that his death was a suicide, Los Angeles County coroner’s Lt. Larry Dietz told the Associated Press.

The two other men killed were Henry Serrano, 56, of Walnut and Robert Lindsay, 53, of Chino, Dietz said.

Two other shooting victims, a man and a woman whose names were not released, were in critical condition at a hospital, the Sheriff’s Department said in a statement.

All five people worked for Southern California Edison in the same area of the same building at an office park in Irwindale, a small industrial city east of Los Angeles, authorities said. Authorities have released no information on a possible motive.

A phone number listed in Turner’s name rang unanswered Saturday morning.

Horrified employees barricaded themselves behind locked doors and hid under desks Friday afternoon as Turner walked through the office firing a semi-automatic handgun, authorities said.

"This is one of the most horrible days in our company’s history," said Edison International Chairman and CEO Ted Craver.

Four of the victims were Edison employees and one was a contract worker, authorities said. Police could not confirm media reports that at least two of the targeted victims were believed to be company managers.

The office complex and nearby schools were locked down as the Los Angeles County Sheriff Department’s SWAT team responded to several 911 calls.

Turner and Lindsay were found dead at the scene, and Serrano died at a hospital, authorities said.

No gunfire was exchanged after officers arrived, and police believed Turner acted alone

"As far as we know there was one shooting suspect, period," Baldwin Park police Capt. Michael Taylor said.

In the hours after the shooting, police cars, ambulances and fire trucks surrounded the building, and dozens of workers emerged with their hands over their heads.

The complex is surrounded by a fence and patrolled by a security guard. Employees need a security card to get into the building, said Gil Alexander, a spokesman for Southern California Edison. About 230 employees work in the building where the shooting took place, and about 1,100 employees work in the complex.

The utility’s office is in a complex of buildings that also includes a business called California Lighting Sales.

Cindy Gutierrez, the controller for that company, said employees there didn’t hear gunshots and didn’t realize anything was amiss until building management announced over the intercom that everyone should stay indoors.

Two nearby schools were locked for about two hours after the shooting and no one on the campuses was hurt.

Irwindale is a city of about 1,400 residents in the San Gabriel Valley, 22 miles east of downtown Los Angeles. It is home to the Irwindale Speedway auto racetrack and large rock and gravel quarries.

Southern California Edison is one of its largest companies, employing 2,100 people.