Rose Esparza, 52, of Dallas was riding the Texas Giant with her family at the Arlington amusement park when she fell off the ride to her death. Her family says the lap bar restraint was not properly engaged before the ride began, allowing Esparza to fly out of the car.
The family has sued Six Flags and the coaster's maker, Gerstlauer, for more than $1 million in state district court in Tarrant County, the Fort Worth Star-Telegram said. The defendants in the case appear to be pointing the finger at one another.
In a cross-filing unveiled this week, Six Flags is suing Gerstlauer for full indemnity, saying the Texas Giant was a "defective product that was unreasonably dangerous in design, manufacture, distribution and promotion."
The German company has 20 days to respond but an attorney representing Gerstlauer told the Dallas Morning News Six Flags was "intimately involved" in design specifications for the coaster.
"This roller coaster was built according to the specific design specifications and was reviewed, tested and approved by Six Flags," attorney Arnd von Waldow said. "Six Flags was intimately involved in the design and production of this roller coaster. ... Six Flags had this designed exactly the way Six Flags wanted it to be designed."
The coaster was closed after the incident in September for two months. Additional lap seat belts were installed as a safety precaution and Six Flags insists the ride is not a danger.
Notable deaths of 2014 [PHOTOS]