Colorado ? Three members of a Kansas family were killed and three other family members were injured just before dawn Saturday in a three-vehicle accident on Interstate 70.

Kenneth Schoenwald, 46, of Wichita, was driving with his family on westbound I-70 when their van collided with the back of a pickup truck being towed by another pickup, the Colorado State Patrol said.

The van spun into eastbound lanes and was then struck by an eastbound semitrailer. No one in the van was wearing a seat belt.

Schoenwald died at the scene along with his 13-year-old son, Jace, and 18-year-old daughter, Jannalea, troopers said.

Janelle Schoenwald, 46, and the couple’s 15-year-old twin daughters, Avery and Alyssa, were flown to hospitals and were in serious condition, the state patrol said.

The cause of the crash was under investigation.