Coolbaugh died after being hit by a line drive while working as a first-base coach in a minor league game.

On July 3, 2007, he was hired as first base coach for the Texas League's Tulsa Drillers, the Double-A affiliate of the Colorado Rockies.

[2][3] The impact pulverized Coolbaugh's left vertebral artery, which supplies significant parts of the brain with blood.

The result, according to Pulaski County coroner Mark Malcolm, was a severe brain hemorrhage killing Coolbaugh on impact; although, CPR kept him from passing.

[1]: 60  [4] Travelers general manager Pete Laven was among the first to reach Coolbaugh, along with Travelers team doctor James Bryan, team athletic trainer Brian Reinker and Gene France, a local doctor who was sitting near the first base dugout with his daughter and a family friend, both of whom are also physicians.

[5] France watched as Bryan administered pain stimulus, applying pressure to various areas of Coolbaugh's body, all with no response.

[12] On November 8, 2007, MLB general managers decided that all base coaches would wear helmets starting with the upcoming 2008 season.