A 5-year-old boy who was in a minivan that was rear-ended by another vehicle at high speed Saturday afternoon in Star has died, according to the Ada County Sheriff's Office. A 7-year-old girl who was in the same vehicle remains hospitalized.

The name of the 5-year-old has not been released. The Ada County coroner will release information about the child on Monday, the sheriff's office says.

The crash happened at 10:51 a.m. Saturday on Idaho 44 at the intersection with Idaho 16.

Investigators said a 41-year-old Star woman — who has not been identified — was driving a 1997 Ford Explorer east on Highway 44. For unknown reasons, she drove into the back of a 1998 Dodge Caravan that was stopped at a red light.

Inside the Caravan were: a 34-year-old woman and three children, 8, 7 and 5, all from Star. The two youngest children were transported to Saint Alphonsus Regional Medical Center.

The driver of the Explorer and her 14-year-old female passenger were also transported to the hospital with injuries that were not believed to be life-threatening. The driver and passenger were not wearing seat belts.

The teenager has been released from the hospital, Ada County Sheriff's spokeswoman Andrea Dearden said.

The driver of the Explorer is believed to have been moving at highway speeds when she crashed into the back of the Caravan. The posted speed limit is 55 miles per hour in that area.

A portion of the intersection was shut down until about 3:20 p.m. Saturday while deputies gathered evidence and information from the crash site.

Dearden said no charges have been filed against the driver of the Explorer; she declined to release the woman's name.