A 4-year-old boy was critically injured Monday when his leg was severed by the bucket of a front-end loader in New Vineyard.

The child was with his grandfather at a family gravel pit off Anson Valley Road when the accident occurred.

The grandfather took his eyes of the child, and the boy got underneath the bucket, which was in the air, said Franklin County Sheriff Scott Nichols Sr.

“It was at that point the bucket lost hydraulic pressure, lowered and captured both legs of the child, severing one,” Nichols told the Sun Journal.

The grandfather wrapped up the child's leg, and then drove the bucket-loader about a half-mile to a truck. The child was then taken by his grandfather to Franklin Memorial Hospital in Farmington.

The boy was later transferred by a LifeFlight helicopter to a Boston hospital.

Nichols said the quick actions taken by the grandfather saved the boy's life.

The accident remains under investigation.