Russell J. Pepiakita, 26, Lawrence, was in serious condition at Kansas University Medical Center, Kansas City, Kan., a hospital spokesman said.
He was transported from the accident scene at K-10 and the East Hills Business Park turn-off by LifeNet helicopter.
Treated at Lawrence Memorial Hospital and released were Lecelia R. Murdock, 22, Cheryl Pepiakita, 6, and Toby A. Pepiakita, 1. They all lived at the same Lawrence address as Russell Pepiakita, a Douglas County Sheriff's report said.
All were in the same vehicle, a 1985 Toyota Corolla, driven by Russell Pepiakita, the report said.
Also taken to LMH and treated and released was John Wagner Jr., 23, Lawrence. Wagner was driving a 1991 Chevrolet Cavalier.
The Cavalier, westbound on K-10, struck the Toyota, which had been eastbound and making a turn onto East 1700 Road, which leads into East Hills, the report said.
Sheriff Rick Trapp said the department's accident reconstruction team is continuing to investigate. A final report could take a few more days, he said.