A collision involving a pickup truck and a box truck on U.S. 30 near North County Road 350 West sent nine people to the hospital Monday evening, prompting an investigation by Indiana State Police.

The crash occurred around 5:40 p.m. when a Chevrolet Silverado, driven by a 44-year-old Warsaw man, attempted to cross U.S. 30. The man reportedly failed to yield to westbound traffic, pulling into the path of a 2011 GMC box truck driven by a 23-year-old Bremen man.

The driver of the box truck and a passenger sustained injuries and were transported to Kosciusko General Hospital. Their conditions were reported as non-life-threatening.

The Warsaw man and a backseat passenger suffered serious injuries and were airlifted to Lutheran Hospital in Fort Wayne. Another adult and four children in the pick-up truck were taken to local hospitals with injuries not believed to be life-threatening.

Authorities say overcrowding in the Chevrolet and the lack of seatbelt use contributed to the high number of injuries.

U.S. 30 was temporarily closed to accommodate emergency air transport and patient care. The investigation remains ongoing.