The man reached over the railing to catch a ball tossed to him by Texas outfielder Josh Hamilton during the second inning of the match between the Texas Rangers and Oakland at the Rangers Ballpark.
After reaching out to catch the ball, the man’s momentum took him over the railings and he fell approximately 20 feet - head first - to a paved area behind the scoreboard, hitting a metal cross beam on the way down, incurring fatal injuries in the process.
(Source)