Investigators have determined that hard-wired smoke alarms were not functioning inside an Encino apartment that was overwhelmed with flames Thursday night, killing an elderly woman and her son and injuring six others.
More than 100 firefighters responded to the blaze, which started just before 9 p.m. inside the three-story apartment building in the 5300 block of Lindley Avenue, Los Angeles Fire Department spokesman Erik Scott said.
Six people, including a firefighter who injured his hand, were hospitalized, he said.
Scott said the mother and son likely died of asphyxiation from smoke. Los Angeles County coroner's officials said it would take days to identify the pair.
Their deaths are the 19th and 20th this year in structure fires in Los Angeles.
Firefighters plan to visit the neighborhood Friday to distribute free smoke alarms and fire safety information to residents.
The cause of the Encino fire remained under investigation.