Oceanside

A 4-year-old boy was killed and eight people were injured, including his parents and sister, Thursday afternoon in a six-car pileup on Interstate 5 about one mile south of Las Pulgas Road, the California Highway Patrol said.

The 1:40 p.m. accident on the southbound lanes of the busy freeway was caused by a dust cloud. It led to the highway’s brief closure and a traffic tie-up three miles long.

Killed in the accident was Jonathan Roberts, 4, of Oceanside, who was riding in the back seat of his parents’ car. His mother, Mary, 34, was taken to Scripps Memorial Hospital-La Jolla with internal injuries. She was listed in satisfactory condition Thursday night.

The child’s father, Stephen, 33, and his sister, Leilanie, 3, were taken to Tri-City Medical Center in Oceanside. They were released after treatment for minor injuries, a hospital spokeswoman said. The family lives in the 700 block of North Cleveland Street in Oceanside.

Also taken to Tri-City Medical Center, where they were treated for minor injuries and released, were Jessica Miller, 20; Oliver Young, 26; Luke Temeyosa, 21, whose addresses were unknown, and Linda Olson, 41, and her husband, David, 40, of El Cajon.