The Los Angeles County Sheriff's Department says deputies from the Norwalk station responded to a rescue call just after 3 a.m. in the 12000 block of Portugal Court.
The men, each in their 30s, were declared dead at the scene.
Authorities say they found chemicals and possible drugs at the location.
A hazmat team and homicide detectives were called to the scene and some neighbors were evacuated for a time.
Additional details, including the names of the victims, were not immediately released.