A woman who told a park employee she didn't feel secure in her seat before a ride at Six Flags in Arlington, Texas fell to her death on Friday after being thrown off a roller coaster.

Rosy Esparza was riding the Texas Giant roller coaster with her two children, when she fell to her death after the coaster took a turn. As the coaster ended its ride, her daughter and son screamed, “My mom! My mom! Let us out, we need to go get her!” Esparza died from her fall at around 6:30 on Friday evening.

"Literally just witnessed someone fly off the Texas Giant two seats in front of me," another passenger of the coaster tweeted. "Restraint came undone, coaster turned and she was gone."

Another passenger on the ride reported to the Dallas Morning News that Esparza had told an employee she didn't feel securely strapped into her seat. “He was basically nonchalant,” the passenger said. “He was, like, ‘As long as you heard it click, you’re fine.’ Hers was the only one that went down once, and she didn’t feel safe. But they let her still get on the ride.”

The Texas Giant, the world’s tallest steel-wood hybrid roller coaster, has been closed pending an investigation of the accident. It had been Esparza's first trip to Six Flags.