Kamber Lett of Orange County said, "Scary, I didn't like it at all."
Kamber Lett and Chuck Lettle were heading home to Orange County when they lost control and wound up on a nearby embankment.
Chuck Lettle said, "There's a ton of mud right there under the underpass, and then my car just basically did a 360 and I ended up off the road."
At least three other cars were in similar situations. The California Highway Patrol says their day was just as sporadic as Wednesday's storm.
Federico Martinez with the California Highway Patrol said, "At times it rains, and it pours, and then we have our accidents, and then the rain lets up and then helps the traffic, but once the rain comes again, we start having accidents again."
Fearing any more accidents, Cal Trans crews brought in heavy equipment, and shut down both lanes every few minutes so workers could clear the mud. The hillside gave way during a heavy downpour of rain and hail.
Reggie Sonier of Selma pulled over during the storm, saying he didn't feel safe enough to continue on.
Reggie Sonier of Selma said, "The highway was at a complete stop. Some cars that were trying to move, they started to slide. I couldn't see anything. it was just all sound. You're completely blanketed with the hail and it just becomes all sound."
Highway 99 was not the only highway impacted by this storm. The stretch of 41 from the South entrance of Yosemite to the Valley floor was closed because of the bad weather.