State police are investigating the weekend crash between an Amish horse-drawn buggy and a logging truck that killed a young boy and his mother and injured his father and two siblings.

The wreck happened about 3:05 p.m. Sunday on Route 208 in Irwin Township, authorities said, about two miles north of the Butler County line.

The buggy was carrying the family of five and was traveling east on the 2400 block of Route 208, also known as Clintonville Road, police said, when it was struck from behind by the log truck.

Authorities have not released the names of the Amish family or the truck driver.

Venango County Coroner Christine Rugh pronounced the boy, believed to be in the second grade, and his mother, believed to be in her early 30s,  dead at the scene. Autopsies are to be performed later today, Rugh said.

The boy's father, who was driving the buggy, and his sister were flown by medical helicopter to St. Elizabeth Boardman Hospital in Youngstown, Ohio and Children's Hospital in Pittsburgh, respectively.

The boy's brother was taken by ambulance to Grove City Medical Center.

The conditions of the injured were not available.

The driver of the truck was apparently not injured. Police said he is “cooperating” with investigators. Venango County District Attorney Shawn White also assisted at the scene.

The crash closed a portion of Route 208 for several hours. Authorities said the horse also was killed.