Although the note was found, authorities are working to determine whether the death was a homicide or suicide, according to the Los Angeles Police Department.
The fire was reported around 9:42 a.m. in the 11920 block of West Weir Street in Del Rey.
Firefighters entered the home to find some smoke and a badly burned female body inside a bathtub in a room that had fire damage but no active flames.
The age and identity of the person have not been identified. Police and fire officials are investigating.