Answer by taking a quote from the following article:

Darrell Lance Abbott (August 20, 1966 - December 8, 2004), also known as Dimebag Darrell and Diamond Darrell, was an American musician and songwriter who was a co-founder of Pantera alongside his brother Vinnie Paul, and founder of Damageplan. He was considered to be one of the driving forces behind groove metal. Abbott was shot and killed by a gunman while on stage during a performance with Damageplan on December 8, 2004, at the Alrosa Villa in Columbus, Ohio. He ranked No. 92 in Rolling Stone magazine's 100 Greatest Guitarists and No. 1 in the UK magazine Metal Hammer.

Abbott formed Pantera in 1981 with his brother Vinnie Paul on drums. Originally, he called himself Diamond Darrell Lance. The band was influenced with thrash metal acts such as Slayer, Megadeth, Venom, and Metallica as well as traditional metal bands such as Black Sabbath, Iron Maiden, Motorhead, and Judas Priest. Shortly after singer Phil Anselmo joined Pantera, Darrell was invited by Dave Mustaine to join Megadeth. Darrell was willing to join, but on the condition that Mustaine also hire his brother Vinnie on drums. As Mustaine already had a drummer, Chuck Behler, Darrell decided to stay with Pantera.  Pantera would go on to become a key formulator of the post-thrash subgenre of "groove" metal. It would not be until nine years after forming that Pantera saw its first piece of commercial success in its 1990 major label debut, Cowboys from Hell. Pantera's "groove" style came to fruition in its breakthrough album Vulgar Display of Power, released on February 25, 1992, which saw the replacement of the power metal falsetto vocals with a hardcore-influenced shouted delivery and heavier guitar sound. On Pantera's 1994 album Far Beyond Driven, Abbott, who'd been listed on all prior albums under the moniker "Diamond Darrell", was listed as "Dimebag Darrell". On the night before Pantera's live appearance at the Monsters of Rock in England's Donington Park, the Abbott brothers got involved in altercations at a local club with journalists from magazines Kerrang! and Raw.  Pantera began to suffer from mounting tensions between band members in the mid-1990s, largely due to vocalist Phil Anselmo's rampant drug abuse.  In 2001, the group went on hiatus, during which time Anselmo worked on side projects, such as Superjoint Ritual and Down. This caused more friction within the band, as the Abbott brothers kept waiting for Anselmo to become available to work with them again. The frustration with Anselmo led to their decision to disband Pantera in 2003.

Did they break up the band?
The frustration with Anselmo led to their decision to disband Pantera in 2003.