11 a.m. Update from City News Service:
A truck crossed the center line of a busy expressway and hit at least four vehicles as it jackknifed across the Chino Valley (71) Expressway, and injured at least five persons, three of them critically.
The truck veered out of control while traveling south on the expressway approaching the traffic signal at Rio Rancho Road, just north of the Pomona (60) Freeway, according to Pomona police sergeant Hector Rodriguez.
Three people were believed to have been trapped in their vehicles for some time, Rodriguez said.
Two Los Angeles County Fire Department medevac helicopters landed on the expressway, and took patents in critical condition to Los Angeles County-USC Medical Center and U.C. Irvine Medical Center, firefighters said.
Ambulances drove a third critical patient, and others, to Pomona Valley Hospital Medical Center for treatment, according to Rodriguez.
"None of their injuries are believed to be life-threatening," Rodriguez told City News Service.
The incident snarled traffic in the area, creating a SigAlert that closed Route 71 north of Route 60. The SigAlert was expected to be lifted sometime after 11 a.m.
A crash involving a big rig and an unknown number of cars has injured several people and forced the closure of the northbound Highway 71 in Pomona.
Officials are warning motorists that northbound lanes will be closed until at least 11 a.m. as investigators sort through the scene to determine exactly what happened.
The crash was reported at 9:06 a.m. just north of Rio Rancho Road. Witnesses told California Highway Patrol officials that a big rig jackknifed and collided with a brown SUV.
Several were seriously injured, according to CHP reports. Diamond Ranch High School was used as a landing area for helicopters that flew the injured to USC Medical Center for treatment, according to reports.
Mortorists are advised to stay away for a few hours if possible. Traffic was being diverted onto the east and westbound Highway 60, CHP officials said.
The investigation continues. This story will updated as information becomes available.