Darrell Lance Abbott (August 20, 1966 – December 8, 2004), also known as Diamond Darrell and Dimebag Darrell, was an American guitarist. He was best known as a founding member of the heavy metal bands Pantera  and Damageplan. Abbott also contributed to the album Rebel Meets Rebel, a collaboration between Pantera and David Allan Coe. Darrell is considered to be one of the driving forces behind groove metal. Abbott was shot and killed while on stage during a Damageplan performance on December 8, 2004, at the Alrosa Villa in Columbus, Ohio.

Source:  http://en.wikipedia.org/wiki/Dimebag_Darrell