The caller did not know which home they were being held in and officers had to go door-to-door looking for the house in the 7900 block of Newcastle Avenue where the call was made.
"We received a 911 call from a cell phone from someone saying they were being held against their will," said Lt. Jeffery Perkins of the Los Angeles Police Department. "They didn't have an address but described the house."
"They were at several different houses with their guns drawn, banging on the doors, going in backyards," said Christina Sandoval, who lives in the neighborhood. "We were wondering what was happening, but never expected that."
When police found the suspected house they entered the home and found 13 undocumented immigrants being held in separate rooms. None of the victims spoke English. Officers said the nine men and four women came from Guatemala, El Salvador and The Dominican Republic.
Neighbors said the house was always well maintained and never thought the people who had just moved in were up to anything illegal.
Immigration and Naturalization Service officials were called out to the home to talk to the victims and take over the investigation.
The people suspected of holding the immigrants were not at the house when police showed up.