The victim, a 55-year-old man, was attacked inside his cable car at about 4:18 p.m. near Mason and Jackson streets while the car was stopped during track maintenance operations, police said.
He was knifed several times in the torso and arm, and was taken to a hospital with life-threatening injuries, but is expected to survive, according to police. The man is a 12-year veteran of the transit agency.
The suspect in the stabbing, George Luong, was to be arraigned in San Francisco Superior Court this morning, but the hearing was postponed because Luong is being held under psychiatric observation at San Francisco General Hospital.
Judge Bruce Chan ordered his bail set at $1 million. Arraignment and a bail hearing are scheduled for Thursday.
Police said witnesses to the stabbing heard “screaming and arguing,” and saw an altercation between the suspect and the victim, but a motive for the attack is still unknown.
Officers tracked Luong down at his home on Himmelmann Place a few blocks away, where they found fresh blood outside the apartment building, and he was arrested.
Three members of Luong’s family were cited for allegedly trying to prevent officers from entering the home.