The incident was reported along Gotera Drive around 9:45 a.m. Firefighters arrived at the scene and found a mudslide in the backyard of one house.
During that investigation, a secondary mudslide occurred and "came crashing down into the neighbor's house," said Los Angeles County Fire Department Engineer Christian Reynoso, a spokesman for the agency.
Both of those affected homes were evacuated, along with a third one at the bottom of the hill that was evacuated as a precaution. No injuries were reported.
La Habra apartment building red-tagged after rain causes wall collapse
La Habra apartment building red-tagged after rain causes wall collapse
AIR7 HD was over the area and observed flooding in the backyard of some homes after the heavy rains.
The full extent of damage to the three houses was not immediately clear.
Plywood and sandbags were being brought to the scene as the cleanup operation continued, Reynoso said.
Two transmission towers are perched atop the hill. Asked if there was any concern about the structures, Reynoso told ABC7: "Yes, there is some concern obviously because they're on that hill that's sliding right now.
"So we're just going to keep an eye on everything and hope for the best, that there isn't any more mud that's coming down."