NORTH LITTLE ROCK, Ark. (AP) – A preliminary autopsy report shows that a burst blood vessel in Mike Coolbaugh’s neck, near his brain, killed the Tulsa Drillers hitting coach when he was hit by a batted ball on Sunday.

“It hit him in the back of the left side of his neck, kind of right below the ear,” Pulaski County coroner Mark Malcolm said.

The ball compressed the left vertebral artery, which travels up the left side of the spinal column and provides blood to the brain. The artery compressed against the vertebra at the top of his spine, right at the base of the skull, and a hemorrhage was the result, Malcolm said.

Malcolm said the full autopsy report has not yet been completed. He would not address whether a helmet would have saved Coolbaugh or whether, in general, a helmet could provide protection from a similarly batted ball.

Coolbaugh was standing in the first-base coaching box when Tino Sanchez of the Drillers lined a ball foul that hit him Sunday night. Medical personnel attended to Coolbaugh on the field, and he was pronounced dead at a hospital at 9:47 p.m., about an hour after he was struck.