He was left alone and couldn’t talk to police. Social media helped find his family | San Luis Obispo Tribune

A young boy found alone at Union Station in Los Angeles on Wednesday night and apparently unable talk to police has been reunited with family, the Los Angeles Police Department said in a tweet Thursday afternoon.

And a woman believed to be his biological mother has been arrested, CBS reported.

"Because the community and media helped spread the word, the LAPD was able to locate family of the found child and reunite them," the department said, adding that the investigation into the incident is ongoing.

Police found the boy about 7 p.m. when a commuter flagged them down, according to the Los Angeles Daily News. In a tweet, the police department said the boy is about 5 to 7 years old.

"We have been unable to communicate with him," the department said.

Police brought in a sign language interpreter to talk to the boy, but he didn't respond, according to the Los Angeles Times. While police initially believed the child was deaf and possibly autistic, the interpreter found that he could hear, according to KTLA.

Employees of Cafe Crepe, a restaurant in the station, told NBC 4 that they saw a woman leave the boy around 6 p.m. and that they tried to get the woman's attention, but she ignored them.

Surveillance footage shows a black woman in her 20s leaving the boy at the station, ABC 7 reported.

"He was still smiling," Adrienne Garrett, a Cafe Crepe employee who tried to talk to the boy, told NBC 4. She added that the boy was running around.

"Maybe if she (the woman) is around, she'll at least see and recognize that, 'Hey, I messed up' and come back," Garrett told the TV station.

LAPD Sgt. Hector Guzman told KTLA that a woman believed to be the boy's mother appeared at Union Station about 2 p.m. Thursday and was taken into custody. Investigators do not yet know whether the woman has legal custody of the child. She was taken to LAPD's Central Station for questioning by detectives, according to CBS.

Details were not immediately available regarding the boy's relationship to the woman who left him at the station, CBS reported, and authorities are interviewing the boy's family to figure out who she is and why he was left there.