The family of a man who was ejected from a rollercoaster at a Six Flags amusement park in Georgia and died has publicly questioned whether the death could have been prevented.

Hassan Jihad Ibn Kariem was riding the Goliath rollercoaster at Six Flags Over Georgia near Atlanta alongside his niece during a family trip to celebrate her birthday when he was thrown from the ride. His niece witnessed her uncle’s death, a relative told the Atlanta ABC News affiliate WSB-TV.

“A large part of me does believe, you know, it was a freak accident, but the other part of me questions … could this have been prevented?” Joshua Nelson, Kariem’s brother-in-law, told the outlet.

Nelson, whose daughter was seated beside Kariem, shared her account of the terrifying moments leading up to her uncle’s death.

“She said he fainted, or passed – her words were ‘he passed out,’” Nelson said. “And then they went up and down, up and down, up and down – and she said it went up again and his latch, I guess, snapped or came loose and he fell,” Nelson remarked.

During the celebratory family outing, Kariem had expressed his excitement about riding the Goliath, which was one of his favorite attractions, according to Nelson.

Nelson said that he hoped Kariem did not experience pain during his final moments.

Kariem was an educator and a father to a 10-year-old daughter. According to Atlanta public schools, Kariem started his career at Wesley International Academy as a technology teacher before being promoted to an information technology manager.

Georgia authorities as of Friday were still investigating the circumstances of Kariem’s death at Six Flags Over Georgia. Cobb county police department’s major crimes unit has launched an investigation.

Since Kariem’s death, Six Flags temporarily closed nine rollercoasters across six amusement parks around the US.