UPDATE: Mother arrested after child abandoned at Union Station, police say
Authorities have described the child as a 5- to 7-year-old black male standing 3 feet 5 inches tall and weighing 60 pounds.
The boy has brown eyes, long black hair that is braided and is wearing a blue down jacket, white tank top shirt, beige pants and grey tennis shoes.
L.A. Police Department officers assigned to the Transit Services Division located the unattended boy around 7 p.m. A sign language interpreter unsuccessfully attempted to communicate with him.
Video surveillance showed a black woman in her 20s abandoning the boy at Union Station, police said.
The child is possibly autistic, according to officials.
Anyone who has seen or has any information regarding the whereabouts of the child are urged to contact the LAPD Transit Services Division at 213-922-1410.