TOWNSEND, Del. (AP) — A Delaware highway crash that killed a New Jersey man and his four daughters is still under investigation.

The family was returning from a trip to Ocean City, Maryland, Friday on U.S. Route 1 when Delaware State Police say a pickup truck crossed the median for unknown reasons and hit the family's minivan and another car.

Police identified the driver of the truck as 44-year-old Alvin Hubbard III of East New Market, Maryland. No charges have been filed.

Police identified the father as 61-year-old Audie Trinidad of Teaneck, New Jersey. News outlets identified the daughters as 20-year-old Kaitlyn, 17-year-old Danna and 13-year-old twins Melissa and Allison.

Police say the mother was hospitalized with serious injuries.