TNT has decided to part ways with the showrunner of Snowpiercer, Josh Friedman. Snowpiercer was ordered to series by TNT earlier this month.

Friedman served as executive producer on the series and wrote the pilot. Sources say that the network cited creative differences for the decision.

The TNT series, which is based on the 2014 Bong Joon Ho film, takes place seven years after the world has become a frozen wasteland and focuses on a small band of people who inhabit a perpetually moving train that circles the globe. Jennifer Connelly stars in the show as Melanie Cavill, who is an important first-class passenger and leader who is fascinated by the less fortunate riders on the train. The cast of Snowpiercer also includes Daveed Diggs, Susan Park, Mickey Sumner, Benjamin Haigh, Sasha Frolova, Alison Wright, Katie McGuinness, Annalise Basso, Sam Otto, Roberto Urbina, Sheila Vand, and Lena Hall.

Friedman’s TV credits include being the showrunner of 2008-2009 Fox drama series Terminator: The Sarah Conner Chronicles and serving as executive producer of NBC’s Emerald City. His film credits include War of the Worlds and Avatar 2.

The pilot of Snowpiercer was directed by Scott Derrickson, and the series is executive produced by Tomorrow Studios’ Marty Adelstein and Becky Clements along with Bong Joon Ho, Park Chan-wook, Lee Tae-hun, and Dooho Choi. TNT’s Snowpiercer is a co-production of Tomorrow Studios and Turner’s Studio T along with CJ Entertainment.