Sheriff's deputies evacuated 80 La Crescenta homes Friday following the discovery of a 5-gallon drum labeled "igniter explosive" inside a vacant house, officials said.
However, the drum was later found to contain only dirty water, said Los Angeles County Fire Capt. Dennis Cross.
The County Fire Department was called to the house in the 4500 block of Sharon Avenue about 2 p.m. when the property owner, who was doing chores, discovered the container.
Families on both side of the home were evacuated to Two Strike Park a few blocks away. The Red Cross assisted in the evacuation.
Arson/Explosives detectives were summoned to the scene, but found no evidence of any device inside or outside the drum, said Deputy Elisabeth Sachs, a Sheriff's Department spokeswoman.
A County Fire Department Hazardous Materials team and sheriff's deputies hauled the container to the Hansen Dam area, seeking a safe place to examine it, and found it contained just water.
Determining the contents took several hours, Cross said.
"They always have to treat it as an explosive unit until they prove otherwise," he said.