FORT WORTH — On the same day that Six Flags Over Texas announced the reopening of the Texas Giant, the family of a Dallas woman killed in July in a fall from the roller coaster sued the amusement park, saying park operators were negligent in not having an adequate restraint system in place despite previous fatalities at other parks.Rosa Esparza, 52, of Dallas was killed July 19 on her first visit to the amusement park in Arlington. The suit says Esparza was upside down in her seat and holding on for “dear life” before she was thrown to her death.The ride was immediately shut down.In a late afternoon news release on Tuesday, Six Flags officials said the internal investigation into Esparza’s death found that mechanical failure was not involved and that the ride would reopen this weekend. The company said it has added “incremental and overlapping safety measures,” including re-designed restraint-bar pads from the manufacturer and new seat belts.The Esparza family’s suit says Six Flags operators have known for decades the risks and extreme dangers posed by such rides, yet failed to make the rides safer until after a serious injury or death has occurred.The suit states that inspections done on the roller coasters since Esparza’s death “showed that various parts of the security systems on the ride were experiencing inconsistencies and intermittent failures.”“In addition, Six Flags has now admitted that, after these inspections, they replaced a ‘limit switch’ for a restraint in the very car in which Rosa was riding because Six Flags found the switch to be defective,” the suit states.The suit does not define what a limit switch is or what it does.“It’s a tragedy of the highest order,” said Dallas attorney Frank Branson, who filed the suit Tuesday in Tarrant County on the family’s behalf. “I believe it should have been avoided and could have been avoided.”The lawsuit names Six Flags Entertainment Corporation, Six Flags Theme Parks, Inc, Texas Flags, Ltd. and Six Flags Over Texas as defendants. The family is seeking more than $1 million in monetary relief.Six Flags said it would not release any further information about the outcome of the investigation conducted by the ride train manufacturer, internal engineers and external experts, according to the news release.“We are heartbroken and will forever feel the pain and sadness of this tragic accident,” said Steve Martindale, president of Six Flags Over Texas. “The safety of our guests and employees is our company’s absolute highest priority and we try to take every reasonable precaution to eliminate the risk of accidents.”Martindale said he and his family would be among the first riders this weekend. The news release did not specify on which day the ride would reopen.Six Flags officials did not respond to a request for comment about the Esparza family’s suit.Esparza’s deathAccording to the lawsuit, Esparza, who has also gone by the last name of Ayala-Gaona, was in the front left seat of the train’s second car behind her daughter and son-in-law. The car had no seat belt or shoulder harness, only a single lap or “T-bar” to restrain passengers.“As the roller-coaster was in its first large descent, Rosa Esparza’s daughter heard screaming and yelling behind her, and turned to see her mother in the process of being thrown out of the car, out from behind the safety in her seat,” the suit states.The suit states that Esparza was thrown against a support piling as the car twisted and turned. “She was then catapulted many feet below onto the metal roof of a tunnel,” the lawsuit states. The Tarrant County medical examiner’s office has estimated that Esparza fell about 75 feet before landing on the tunnel’s roof.“Her daughter and son-in-law were forced to complete the ride for what seemed like an interminable time, knowing that Rosa Esparza had been thrown out of the ride and not knowing whether she was dead or seriously injured and in need of immediate medical attention,” the suit states.When the ride finally returned to the station, Six Flags employees initially refused to believe Esparza’s daughter and son-in-law’s account that their mother had been thrown out, the suit states.“An agonizing period of time passed before Rosa Esparza was located at the top of the tunnel,” the suit states.The Six Flags news release on Tuesday said the park will provide a coaster ride seat at the ride entrance so guests can test their fit before entering the ride line, because guests with “unique body shapes and sizes” may not fit into a ride’s restraint system.The Texas Department of Insurance has given the park approval to resume the ride’s operation.Problems with rideThe lawsuit alleges that Six Flags used a green-light system that reportedly would not allow a train to be dispatched unless each safety bar restraint was in the “proper position.”“This system of lights was confusing and dangerous because it had a tendency to create a false sense of security and complacency on the part of the operators of the ride” who might not then undertake further checks of the restraint, the suit states. The suit alleges that inspections later found there were inconsistencies in the relative locking positions of the safety bars on the train’s cars, as well as failures found in the green light system.Six Flags has also acknowledged that, after these inspections, they replaced a defective “limit switch” for a restraint in a seat in the very car in which Esparza had been riding, according to the suit.The suit names several other incidents dating back to 1978 in which people were seriously injured or killed in roller coaster accidents at other Six Flags parks.“More often than not, the response of the Six Flags defendants to roller-coaster tragedies at their parks has been merely to feign surprise and to belatedly add safety belts in an attempt to calm the public’s fears,” the lawsuit states.Six Flags officials knew, or should have know, the danger of ejection that an “inadequate” restraint system posed to riders, the suit states.“You can do shoulder harnesses. You can do lap belts. I think any of the above may well be safer designed that what they were using out there that day,” Branson said. “… It was unreasonably dangerous.”The Texas Giant, which rises 14 stories high and has a 79-degree first drop (the steepest in the world for a wooden roller coaster), has been closed since Esparza’s death.