Lonnie Glasco (left) shot and killed Benjamin Mwangi, 37, at an MTS yard in the wee hours of Tuesday morning, according to police.
San Diego homicide detectives are trying to determine a motive for a deadly shooting rampage by a bus mechanic who was later fatally gunned down by police at the Metropolitan Transit System's East Village bus compound early Tuesday.
The mechanic -- identified as Lonnie Glasco, 47 -- "became irrational" shortly after clocking out of an eight-hour shift that ended at 2 a.m., according to Police Capt. Jim Collins.
"He went into an office, brandished a weapon, and told several people in there that they weren't going to be leaving," Collins told reporters.
Collins said Glasco, a fare-box repairman and 29-year MTS employee, left the room after an exchange of conversation, and that the others soon heard shots fired, then found 37-year-old Benjamin Mwangi, a transit foreman, dying of a head wound on the ground.
"Witnesses started running from the area, they heard another shot fired, and police were called," Collins said.
The suspect's second shooting victim, a 55-year-old mechanic with 31 years of MTS service, was hospitalized and placed on life support. Police are withholding his identity for the time being.
Officers who confronted Glasco told investigators he refused repeated demands to drop his revolver, made a call on his cellular phone, then lowered it and raised the weapon toward the police.
Said Collins: "Three officers opened fire, striking (Glasco)," who died at the scene.
Collins said he was not aware of a history of discord between Glasco and Mwangi, or the wounded mechanic.
A friend of the suspect said Glasco had recently been despondent over losing his wife and his home.
He said detectives will examine MTS security camera videotape to help piece together the deadly episode of workplace violence.
According to Collins, investigators have identified the person who received the cell phone call from Glasco, but are not releasing a name.
MTS employees at the transit compound, located at 16th Street and Imperial Avenue, were advised in a company memo not to share information about the rampage with anyone but grief counselors and police.
"We're in shock," an MTS bus driver told NBCSanDiego.com, declining to give his name or be interviewed on camera.
"Three people who knew each other -- two of them dead. It's a shock."