A construction company was installing sewer lines when crews had to halt construction due to the rain. They weren't able to fill the trenches and there was a lot of loose debris on both sides.
Structural engineers say the construction sites are sound. The houses are actually built on top of pile-ons, which are drilled into bedrocks, so there's no fear of those homes slipping.
There is concern about the hillside.
Neighbors say that around 3:30 a.m. the mud started sliding down. Firefighters are concerned about the hill. They're going to keep a close eye on the hill, but they say they've got some other precautions in place to try and keep the ground steady.
"We've also got some K-rail coming in, that cement stuff you see in the middle of the freeways," said John Duca, Los Angeles City Fire. "It's going to come in and be put on the sidewalk on this side to hopefully divert some of flow. We've got sandbagging going on, so we're trying to mitigate as much as we can, as soon as we can."
As a result of the mudslide, two homes below the hill have yellow-tagged. It's not mandatory for the occupants to evacuate, but the houses are being watched.