Earlier today the gaming world learned of the termination of long-time composer Martin O’Donnell from Bungie, via a tweet O’Donnell sent out from his Twitter account.

I’m saddened to say that Bungie’s board of directors terminated me without cause on April 11, 2014.

— Marty O’Donnell (@MartyTheElder) April 16, 2014

O’Donnell has done work for the company since 1997, starting with the game Riven and eventually composing the music for a then-secret project which would become the first Halo game – Halo: Combat Evolved. He then joined the company in 2000, shortly before Microsoft acquired the company. O’Donnell has composed music for the Halo games all the way through to Halo: Reach, meaning he is responsible for some of the acknowledgedly awesome music heard throughout the series’ games. He had also been working on music for the upcoming game Destiny.

Bungie posted a message on their website acknowledging the composer’s leaving of their company and offering him a brief farewell.

“For more than a decade, Marty O’Donnell filled our worlds with unforgettable sounds and soundtracks, and left an indelible mark on our fans. Today, as friends, we say goodbye. We know that wherever his journey takes him, he will always have a bright and hopeful future.

We wish him luck in all his future endeavors.”

The reason for O’Donnell’s termination still remains unclear.

O’Donnell’s Tweet is here.

Bungie’s post is here.