LOUISVILLE, Ky., July 23 (UPI) -- A 2-year-old Kentucky boy died after being accidentally hit by a bat a sibling was swinging on a t-ball field in the Louisville area, officials said.

The children were with a YMCA group that was playing Tuesday night, WAVE-TV, Louisville, reported. A coach told the television station that the death was "the worst event of my life."

"We're not sure how the children came to be close enough to each other for this to occur," said Steve Tarver, president and CEO of YMCA of Greater Louisville. "It would have had to happen in just an instant and as we say it's simply a very tragic accident."

The dead boy was identified as Henry Berlin. The cause of death, according to the autopsy, was blunt force trauma to the chest, causing a heart irregularity.

Tarver confirmed that the child swinging the bat was a sibling of the dead boy.