Madness!

Twin tornadoes touch down Thursday near March Air Force Base in Riverside. The funnels caused power outages, derailed a train, and flipped a big rig truck forcing the 215 Freeway to close, but no injuries were reported.

Tornadoes in Riverside County derailed a freight train and flipped a big rig. Orange County saw massive mudslides, while L.A. County faced flash-flood warnings and closure of the 10 Freeway.

A tornado flipped a big-rig truck, derailed a freight train and clogged a major interstate for several miles Thursday as a wild spring thunderstorm hopscotched across Southern California dumping hail, rain and snow.

The most severe damage was reported in Riverside County, where dark, towering funnel clouds spun across the communities east and west of the 215 Freeway corridor. In Orange County, walls of water, mud and debris -- some 8 feet high -- battered eastern canyons that had burned in last year's wildfires, leaving behind a muddy mess but little major damage and no injuries.

The highly unstable and unpredictable conditions were expected to last through today, along with unseasonably cool temperatures, according to the National Weather Service.

Shortly before 5 p.m. Thursday in Riverside County, one of two funnel clouds tossed a line of 30-ton rail cars off their tracks and overturned a tractor-trailer truck, blocking the northbound lanes of the 215 Freeway. Rush-hour traffic backed up for at least eight miles, according to the California Highway Patrol.

The truck driver was pulled from the wreckage and taken to a hospital with minor to moderate injuries.

"It's quite large," CHP officer Jaci Parent said of the tornado as it churned west of the interstate Thursday evening.

The tornado then headed toward Perris, where it caused power outages and minor damage before dissipating.

"I drove through it and have never seen weather like this," said Sgt. Dennis Gutierrez, spokesman for the Riverside County Sheriff's Department.

A blanket of hail turned neighborhoods white in Baldwin Park and Irwindale, drawing crowds of children into the streets to play with the ice. Snow dusted higher elevations and lightning strikes were reported in Mira Loma and other inland areas as the storm drifted south and west.

As storm cells jumped from place to place through the day, radio and television broadcasts were interrupted with emergency warnings for communities threatened by flooding and tornadoes.

Slush, flooding and rock slides closed sections of Interstate 10 in central Los Angeles County and the 60 Freeway east of Riverside.

There were reports of a tornado touching down near Interstate 15 in Corona on Thursday night. Parent said investigating officers found a severe storm and flooded freeway lanes, but no funnel cloud.

In Orange County, eastern canyons saw roughly 1 1/2 inches of rain in a half-hour period, authorities said.

Officials closed the roads to mud-swept Modjeska, Silverado and Williams canyons and worked to rescue residents stranded in two homes near the back of Williams Canyon. They were not hurt and were waiting for roads to clear so they could evacuate, said Mike Blawn, a spokesman for the Orange County Fire Authority.

Authorities dispatched bulldozers and other heavy equipment to clear the roadways and stand by in the event of more heavy rains.

Two canyon residents barely escaped the avalanche of boulders, mud and tree trunks that went roaring at them in Modjeska Canyon.

"It was out of control," said Tim Adams, 56, a resident of nearby Silverado Canyon who went to help his brother-in-law, Bill LaBar. "It was like big chunks of chocolate ice cream melting, with trees and rocks flowing through it."

Adams and LaBar got into four-wheel drive vehicles and sped away, going around and over boulders and downed trees.

"I have always said when it got bad, I would get out," said LaBar, who usually ignored mandatory evacuation orders. "It's the baddest I've ever seen it."

At Cook's Corner, a roadside biker bar in Trabuco Canyon, about a dozen people were eating burgers and omelets when water and mud poured into the restaurant about 12:15 p.m.

-Rei