He was killed in the 2011 Lokomotiv Yaroslavl air disaster, in which all players and coaches on board the plane from the club perished. Dietrich was drafted 174th overall in the 6th round of the 2007 National Hockey League Entry Draft by the Nashville Predators. He played with the DEG Metro Stars of the DEL from 2005 to the 2008.
On July 16, 2007, Dietrich was signed to a three-year entry level contract with the Predators.
He was reassigned on loan to the Metro Stars for his first year of the contract, before he spent the final two seasons in North America with the Predators American Hockey League affiliate, the Milwaukee Admirals. In his second year with the Admirals in 2009-2010, he led the team with 43 points for defenseman, but was unable to appear in the National Hockey League with Nashville.
On June 8, 2010, Dietrich returned to Germany and signed a two-year contract with Adler Mannheim. On September 7, 2011, he was killed when a Yakovlev Yak-42 passenger aircraft, carrying nearly his entire Lokomotiv team, crashed just outside Yaroslavl, Russia.
The team was traveling to Minsk to play their opening game of the season, with its coaching staff and prospects.
Lokomotiv officials said "everyone from the main roster was on the plane plus four players from the youth team".