ANAHEIM HILLS, Calif. (KABC) -- Heavy rain caused mud, debris and rocks to fall onto the eastbound 91 Freeway in Anaheim Hills Wednesday morning.
The mudslide occurred at Gypsum Canyon Road around 2 a.m., shutting down all seven eastbound lanes.
Motorcyclist Jeff Dean of Mira Loma was among those caught in the middle of the mess.
"The mountain slid out, had a big mudslide come down from the mountain and cover the whole freeway," said Dean.
Two other drivers within the slide zone were involved in a fender bender. No injuries were reported.
Other cars were stuck with flat tires from all the rocks on the roadway.
For more than five hours, Caltrans crews worked -- under steady rainfall at times -- to clear the highway.
By 7:15 a.m., the FasTrak lanes and three eastbound lanes reopened. Caltrans said the FasTrak lanes would be free for drivers during the cleanup in order to help alleviate traffic.
The remaining two lanes were to remain closed until at least 2 p.m. The northbound 241 Freeway connector to the 91 East was also closed.
This is the same hillside that was charred in a 40-acre fire three months ago. Because of the fire, Caltrans officials say they were prepared for the slide to happen and had cement K-rails already on site. Perhaps what they were not prepared for was the consistency of the wet mud.
"The (mud) slurry still stays on the road, so you sweep it multiple times and try to get as much off as you can, but it's still a little slick," said David Richardson with Caltrans.
The California Highway Patrol is advising motorists to be prepared for something like this to happen when winter storms pass through.
"The speed limit may be 65, but that's in perfect conditions. When it's raining or low visibility, you have to slow down, drive slower than that," said CHP Officer Paul Fox.