Four children killed in a multi-vehicle crash in northeastern Pennsylvania were not in booster seats or wearing seatbelts when the car in which they were traveling caused a high-speed, four-car crash, police said Sunday.

The Saturday afternoon crash killed five, including the 23-year-old woman driving the car in which the children were riding, the Pennsylvania State Police said. Three other people went to hospitals.

Police did not disclose the identities of the children or their relationship to the dead woman, Destini Watson, of Blakeslee. An adult passenger in Watson's car, Monisha Roberts, 21, survived after being ejected from the vehicle.

Watson, Roberts and the drivers of the three other vehicles were wearing seatbelts, but the children were not restrained, police said.

Police say the pileup happened after Watson tried to pass another vehicle at a high rate of speed on Route 115 in Monroe County, about 70 miles north of Philadelphia.

Watson passed the car and began moving back into the southbound lane when she lost control of her vehicle and swerved into the northbound lanes. Her vehicle struck a second vehicle, flipped onto its side and struck a third vehicle. A fourth vehicle crashed into the third, police said.

Roberts and the drivers of the second and third vehicles -- Harold Roberts, 77, and Wade Hunter, 53 -- were taken to hospitals. The driver of the fourth vehicle, Patrick Mikolaitis, 41, suffered minor injuries, police said.

Police said they were still investigating the accident.