The man operating the tractor lost control of the vehicle and traveled down an embankment, where it overturned, throwing everyone from the trailer, said Lt. Adam Reed, director of communications for the Pennsylvania State Police.
A woman and three children were killed and eight other children were injured, Reed said. The extent of their injuries is unknown and three of the injured were taken from the scene to hospitals for treatment, he added.
The flatbed trailer was open and had a two-foot fence around it, Reed said.
A criminal investigation unit, a forensics team and a collision analysis and reconstruction specialist are investigating the scene in Lower Chanceford Township, Reed said.
“The road remains closed and the incident is still very actively under investigation, but it’s obviously a very tragic scene for all the first responders down there,” Reed said. “Our hearts go out to the families of the youngsters and everyone involved. It’s a very tough day for everyone down there.”
“It’s very sad, very tragic, especially any time lives were lost, but especially when children are involved as well,” Reed added.